S uc u e and Reac i i y o Te es ial and
Ex a e es ial Py ho i e
Von de Fakul ä ü Biologie, Chemie und Geowissenscha en
de Uni e si ä Bay eu h
zu E langung de Wü de eines
Dok o s de Na u wissenscha en
− D . e . na . −
genehmig e
Disse a ion
Vo geleg du ch
Dennis Ha ies, Dipl.-Geow.
aus Seesen am Ha z
Bay eu h 2012
Die o liegende A bei wu de in de Zei on Sep embe 2008 bis Janua 2012 in Bay eu h
am Baye ischen Geoins i u un e Be euung on He n P o . D . Falko Langenho s und
D . Kilian Pollok ange e ig .
Volls ändige Abd uck de on de Fakul ä ü Biologie, Chemie und Geowissenscha en
de Uni e si ä Bay eu h genehmig en Disse a ion zu E langung des akademischen
G ades eines Dok o s de Na u wissenscha en (D . e . na .).
Disse a ion einge eich : 12. Janua 2012
Zulassung du ch die P omo ionskommission: 18. Janua 2012
Tag des wissenscha lichen Kolloquiums: 30. Ap il 2012
Am ie ende Dekan:
P o . D . Bea e Lohne
P ü ungsausschuss:
P o . D . Falko Langenho s (E s gu ach e )
P o . D . He be Palme (Zwei gu ach e )
P o . D . S e an Pei e (Vo si z)
P o . D . Tomoo Ka su a
P o . D . Leonid Dub o insky
2
Abs ac
Py ho i e (Fe1-xS) is a non-s oichiome ic i on monosul ide common in e es ial ocks,
o e deposi s, and many ex a e es ial ma e ials. The non-s oichiome y due o me al
acancies ela es o a a ie y o composi ion-dependen c ys allog aphic supe s uc u es,
bu li le o he exis ing s uc u al and mic os uc u al complexi y has been explo ed ye .
This hesis in es iga es he occu ences and na u e o py ho i e supe s uc u es, examines
he ela ed nano- and mic os uc u al phenomena, and explo es hei e ec s on chemical
eac i i y. The goal is o comp ehend he ela ions o he nanoscale eal s uc u e o
py ho i e o i s physicochemical p ope ies. A cen al ool in hese s udies is analy ical
ansmission elec on mic oscopy (TEM), which has been ex ensi ely used o s udy
e es ial and ex a e es ial samples. In h ee s udies, published o submi ed as scien i ic
esea ch a icles, i is shown ha s uc u al complexi y o py ho i es is a widesp ead
ea u e in e es ial and ex a e es ial ma e ials and is s ongly in e ela ed wi h i s
physicochemical p ope ies and en i onmen s o o ma ion and al e a ion. A new model
based on ansla ion in e ace modula ion is being in oduced o p o ide a ealis ic
desc ip ion o he s uc u al s a e o na u al NC-py ho i es. No el insigh s in o he
he modynamically s able phase assemblages in he Fe-S sys em a ambien empe a u es
a e p esen ed and he c ys allog aphy and connec ed he mochemis y o py ho i es a e
deployed o each new conclusions abou he pe ogene ic his o y o chond i ic me eo i es
and he al e a ion p ocesses hey we e in ol ed in. Finally, an expe imen al al e a ion
s udy e eals o he is ime quan i a i ely ha he acancy supe s uc u es and
aniso opy o py ho i es ha e emendous e ec s on hei kine ic beha io s du ing
dissolu ion unde acidic and oxidizing condi ions. In insic eac i i y di e ences be ween
4C- and NC-py ho i e a e clea ly esol ed and discusses in he amewo k o he newly
es ablished s uc u e model.
3
Zusammen assung
Py ho in (Fe1-xS) is ein in e es ischen Ges einen, E zlage s ä en und ielen
ex a e es ischen Ma e ialien e b ei e es, nich s öchiome isches Eisenmonosul id. Die
Nich s öchiome ie du ch Me alllee s ellen s eh in Ve bindung zu eine Vielzahl
k is allog aphische Übe s uk u en, die on de Zusammense zung abhängig sind, jedoch
hinsich lich ih e s uk u ellen und mik os uk u ellen Komplexi ä bislang wenig
e o sch wo den sind. Diese A bei un e such die Vo kommen und Eigenscha en de
Py ho inübe s uk u en, behandel die in Beziehung s ehenden nano- und
mik os uk u ellen Phänomene und e o sch ih e E ek e au die chemische Reak i i ä .
Das Ziel is , zu e s ehen, in welchem Ve häl nis die nanoskaligen Reals uk u en des
Py ho ins zu seinen physikochemischen Eigenscha en s ehen. Im Rahmen de S udien
wu de o allem analy ische T ansmissionselek onenmik oskopie (TEM) als wich igs e
Me hode e wende , um e es ische und ex a e es ische Py ho ine de aillie zu
un e suchen. In d ei A bei en, die als wissenscha liche Fo schungsa ikel en wede
einge eich ode schon publizie wu den, wi d gezeig , dass die s uk u elle Komplexi ä
de Py ho ins ein wei e b ei e es Me kmal in e es ischen und ex a e es ischen
Ma e ialien is und in engem Zusammenhang mi seinen physikochemischen
Eigenscha en und den Bildungs- und Al e a ionsbedingungen s eh . Es wi d ein neues
Modell einge üh , welches basie end au T ansla ionsg enz lächenmodula ion eine
ealis ische Besch eibung des s uk u ellen Zus andes na ü liche NC-Py ho ine
e möglich . Neue Einsich en zu den he modynamisch s abilen Phasenbeziehungen im Fe-
S Sys em bei Umgebungs empe a u we den p äsen ie , und die K is allog aphie und die
dami e bundene The mochemie de Py ho ine we den genu z , um neue E kenn nisse
übe die pe ogene ische En wicklung chond i ische Me eo i e und ih e
Al e a ionsp ozesses zu gewinnen. Zum Abschluss wi d in eine expe imen ellen S udie zu
e s en Mal quan i a i gezeig , dass die Lee s ellenübe s uk u en und die Aniso opie de
Py ho ine einen eno men Ein luss au das kine ische Ve hal en wäh end oxida i e
Au lösung un e sau en pH-Bedingungen ausüben. Die in insischen
Reak i i ä sun e schiede zwischen 4C- und NC-Py ho in we den eindeu ig au gelös und
im Rahmen des neu einge üh en S uk u modells disku ie .
4
Acknowledgemen s
I am g a e ul o P o . D . Falko Langenho s and D . Kilian Pollok o p o iding he
chance o wo k on his p ojec wi h g ea la i ude o my own ideas, as well as o hei
guidance and suppo . Wo k in he co dial and highly p o essional en i onmen o he
Baye isches Geoins i u was a g ea pleasu e and I co dially hank all o i s p esen and
pas membe s o sus aining i . Pa icula hanks go o Hube Schulze and Uwe Di mann
o hei excellen sample p epa a ion, o Heinz Fische and S e an Übelhack o swi and
p ecise machining o all he bi s and pieces needed in my esea ch, and o Julia Hube ,
Ge ud Gollne , Pe a Buche , Lydia Kison-He zing, De le K ausse and D . S e an
Keyssne o hei help and suppo . D . Nobuyoshi Miyajima is specially hanked o his
kind help and main enance o BGI’s TEM labo a o y. D s. Tiziana Bo a Balla an and
Flo ian Heidelbach a e hanked o hei suppo in he X- ay di ac ion and SEM
labo a o ies, espec i ely. I hank P o . D . He be Palme o his willingness and ime o
p o ide he second e alua ion o his hesis.
My o ice ma es and ellow colleagues a e co dially hanked o hei suppo , iendship,
and many ba becue pa ies. Pa icula hanks go o Linda Le chbaume , Vincenzo S agno,
Kons an in Glazy in, Gee je Ganskow, An je Vogel, Ma ha Pama o, and Ma ia Giannini.
Samples used in his wo k we e p o ided by he Mine alogical Collec ion and Museum o
he Uni e si y o Jena, and he Japanese Na ional Ins i u e o Pola Resea ch.
This esea ch was unded by he GEOTECHNOLOGIEN R&D p og am g an (03G0718A
o K.P.), which i sel is unded by he Ge man Minis y o Educa ion and Resea ch
(BMBF) and Ge man Resea ch Founda ion (DFG). I was inancially suppo ed by he
DFG Leibniz p og am (LA 830/14-1 o F.L.) and he ENB p og am “S uc u e, Reac i i y
and P ope ies o Oxide Ma e ials” o he Ba a ian S a e Minis y o Sciences, Resea ch
and he A s. I pa icula ly hank he la e o p o iding a el unding and suppo o
s uden semina s and sho cou ses. T a el unds and awa ds we e g an ed o me by he
Me eo i ical Socie y and he Deu sche Mine alogische Gesellscha , and I g a e ully
acknowledge hese.
Las bu no leas I would like o hank my pa en s Gab iele Ha ies and O ma Ha ies o
hei cons an suppo .
5

TABLE OF CONTENTS
Abs ac 3
Zusammen assung 4
Acknowledgemen s 5
Table o Con en s 6
Lis o Figu es 10
Lis o Tables 12
CHAPTER 1 In oduc ion
1.1. Mo i a ion and Backg ound 13
1.1.1. Mo i a ion 13
1.1.2. Modula s. Modula ed S uc u es in Mine alogy 14
1.1.3. Py ho i e in Ea h and Plane a y Ma e ials 18
1.1.4. Oxida ion and Dissolu ion o Py ho i e 21
1.2. No el and Specialized Me hods 23
1.2.1. Focused Ion Beam P epa a ion 23
1.2.2. TEM Supe s uc u e Da k-Field Imaging 25
1.2.3. Quan i a i e 3D Topome y 27
1.3. De ailed Summa y and Linkage o Resea ch S udies 29
1.4. Au ho Con ibu ions 33
1.5. Publica ions Connec ed o This Disse a ion and Rela ed
Wo k 34
CHAPTER 2 T ansla ion In e ace Modula ion in NC-Py ho i e: Di ec
Imaging by TEM and a Model owa d Unde s anding
Pa ially Diso de ed S uc u al S a es
2.1. Abs ac 36
2.2. In oduc ion 37
2.3. Samples and Expe imen al Me hods 42
2.4. Resul s 43
2.4.1. EPMA/SEM-BSE 43
2.4.2. TEM-SAED 46
2.4.2.1. Choice o Supe cell and De e mina ion o
S uc u e Pa ame e s 46
2.4.2.2. Geome ical Analysis o Di ac ion Pa e ns 48
6
2.4.3. Supe s uc u e Da k-Field Imaging (SDF-TEM) 50
2.4.4. High Resolu ion Imaging (HR-TEM) 55
2.5. Discussion 57
2.5.1. A T ansla ion In e ace Modula ion Model o
NC-Py ho i es 57
2.5.2. S uc u al O ganiza ion a Phase In e aces 61
2.5.3. Implica ions and Ou look 62
2.6. Acknowledgemen s 65
CHAPTER 3 The Nanoscale Mine alogy o Fe,Ni Sul ides in P is ine and
Me amo phosed CM- and CM/CI-like Chond i es: A emp ing
o Tap a Pe ogene ic Reco d
3.1. Abs ac 66
3.2. In oduc ion 67
3.2.1. CM and CM/CI-like Chond i es 67
3.2.2. P e ious Wo k and Cons ain s on Me amo phic
His o ies 68
3.2.3. Py ho i es in he Fe(+Ni)-S Sys em 70
3.3. Sample P epa a ion and Analy ical Me hods 73
3.3.1. Sample P epa a ion 73
3.3.2. Analy ical Me hods 73
3.4. Resul s 74
3.4.1. SEM and EPMA Obse a ions 74
3.4.1.1. Yama o-791198 74
3.4.1.2. Yama o-793321 76
3.4.1.3. Belgica-7904 78
3.4.1.4. Yama o-86720 79
3.4.2. Composi ions in he Fe-Ni-S Te na y 80
3.4.3. TEM Obse a ions 81
3.4.3.1. Yama o-791198 81
3.4.3.2. Yama o-793321 85
3.4.3.3. Belgica-7904 87
3.4.3.4. Yama o-86720 89
3.5. Discussion 90
3.5.1. Sul ide Fo ma ion by Nebula Condensa ion
P ocesses 90
7
3.5.2. Pa en Body Aqueous Al e a ion s. Nebula
P ocesses 94
3.5.3. Low G ade Pa en Body Me amo phism 95
3.5.4. High G ade Pa en Body Me amo phism 98
3.5.5. Rela ions among Me amo phosed and P is ine
CM/CI Chond i es 100
3.6. Conclusions 101
3.7. Acknowledgemen s 103
CHAPTER 4 Oxida i e Dissolu ion o 4C- and NC-Py ho i e: In insic
Reac i i y Di e ences, pH Dependence, and he E ec o
Aniso opy
4.1. Abs ac 104
4.2. In oduc ion 105
4.2.1. Gene al In oduc ion 105
4.2.2. Mine alogy o Py ho i e 105
4.2.3. Reac ions a Py ho i e Su aces 106
4.2.4. Ou line o App oach 108
4.3. Samples and Expe imen al P ocedu e 109
4.3.1. Sample Desc ip ion 109
4.3.2. Sample P epa a ion 109
4.3.3. Expe imen al Se up and Condi ions 114
4.3.4. Analy ical Me hods 115
4.4. Resul s 118
4.4.1. Gene al Obse a ions and Iden i ica ion o Al e a ion
Phases 118
4.4.1.1. Expe imen s wi h FeCl3 Solu ion−Su ace
Mine alogy 118
4.4.1.2. Expe imen s wi h FeCl3 Solu ion−Py ho i e
Reac i i y and Expe imen al Rep oducibili y 120
4.4.1.3. Expe imen s wi h H2O2 Solu ion−Su ace
Mine alogy 121
4.4.2. Phase-speci ic Quan i ica ion o Dissolu ion Ra es
om H2O2 Expe imen s 122
4.4.2.1. Reac i i y o NC-Py ho i e s. 4C-Py ho i e 122
4.4.2.2. E ec o Addi ional Solu es 126
8
4.4.3. O ien a ion Dependence o Py ho i e Dissolu ion 126
4.4.3.1. Reac ion a pH 2.05 127
4.4.3.2. Reac ion a pH 2.88 o 2.92 127
4.4.3.3. Con ol o Supe s uc u e on Dissolu ion
Aniso opy 128
4.4.3.4. Anomalous Dissolu ion Beha io in
Mic oen i onmen s 128
4.4.4. In e ace Mo phology 129
4.4.5. HR-TEM In e ace Obse a ions 131
4.5. Discussion 133
4.5.1. pH Dependence o Dissolu ion Ra es and Aniso opy 133
4.5.1.1. Dissolu ion Ra es and he Isoelec ic Poin 133
4.5.1.2. Dissolu ion Aniso opy and Chemical S a e o
Py ho i e Su aces 134
4.5.1.3. Oxidan Species 135
4.5.1.4. Non-oxida i e Dissolu ion and he Role o Fe3+ 136
4.5.2. Reac i i y Di e ences be ween 4C- and NC-Py ho i e 136
4.5.3. Exis ence o Sul idic Non-equilib ium Laye s 139
4.6. Conclusions 140
4.7. Acknowledgemen s 140
BIBLIOGRAPHY 141
ERKLÄRUNG 154
9
CHAPTER 1 INTRODUCTION
FIGURE 1-2. Basic building modules o py ho i e in he poly ype model. Sul u a oms a e
yellow, i on a oms a e b own. (a) I on is six old coo dina ed by sul u and o ms shee s o edge-
sha ing oc ahed a. Fou di e en i on posi ions (A o D) a e dis inguished in he model. (b) One
o ou laye s bea ing i on-si e acancies, he e he B posi ion is shown acan . The laye is he
nex uni o be s acked on he laye shown in (a). The s acking di ec ion is ou o he pape plane
and s acking esul s in ace-sha ing o he oc ahed a.
In p inciple, he a ailable i e ypes o laye s in py ho i e o e in ini e s acking
combina ions, bo h pe iodic and ape iodic ones. Al hough he la e may appea on i s
sigh incompa ible wi h he classical de ini ion o a c ys al as a “solid composed o a oms
a anged in a pa e n pe iodic in h ee dimensions” (Culli y 1956), some ape iodic
s acking sequences would indeed posses “quasipe iodic” p ope ies ha allow he solid o
p oduce well de ined B agg di ac ion (Bu ows and Suls on 1991) in acco dance wi h
he mode n de ini ion o a c ys al as a “solid ha ing an essen ially disc e e di ac ion
diag am” (IUC 1992). Such quasipe iodic sequences a e non- epea ing, bu ollow s ic ,
de e minis ic pa e ns and ha e long- ange o de (as opposed o s ochas ic a angemen s,
which would ha e missing o s eaky di ac ion along he ecip ocal s acking di ec ion).
In ac , he so-called non-in eg al NC-py ho i es a e a odds wi h classical
c ys allog aphy, because hei sha p di ac ion pa e ns canno be eadily indexed by
assuming h ee-dimensional pe iodici y since he appa en epea dis ances imply non-
in eg al o e en i a ional mul iples o he basic s acking uni s/laye s (Mo imo o and
Nakazawa 1968; Nakazawa and Mo imo o 1970).
16

CHAPTER 1 INTRODUCTION
A ma hema ically elegan way o econcile long- ange o de and ape iodici y in a
desc ip i e model applicable o many quasipe iodic solids is he “supe space modula ion”
app oach o de Wol , Janne and Janssen (de Wol e al. 1981 and e . he ein; Chapuis
2003; an Smaalen 2004). This app oach desc ibes h ee-dimensional c ys al s uc u es
wi h one ape iodic di ec ion as slices ou o ully pe iodic, ou -dimensional s uc u e
ep esen a ions (analogous o a wo-dimensional c oss-sec ion ob ained by slicing a h ee-
dimensional objec ). In his (3+1)-supe space indi idual a omic posi ions wi hin he uni
cell a e no longe ze o-dimensional poin s bu one-dimensional (line-)objec s wi h an
assigned modula ion unc ion, which speci ies displacemen o occupancy o an a omic
si e as a unc ion o posi ion along he di ec ion o he ex a dimension. The loca ion o he
h ee-dimensional in e sec ion wi h he modula ion unc ion de e mines he eal a omic
displacemen s and occupancies, and whe he he esul ing s uc u es a e pe iodic o
ape iodic. The s uc u e is said o be one-dimensionally modula ed. The necessi y o
desc ibe one-dimensionally modula ed, ape iodic s uc u es in (3+1)-dimensional uni
cells becomes appa en om he geome y o di ac ion pa e ns, because hey need ou
in ege s o be indexed p ope ly (some imes e en mac oscopic c ys al o ms need ou
in ege s o be indexed, e.g., Chapuis 2003).
A i s applica ion o he supe space app oach o py ho i e was published by
Yamamo o and Nakazawa (1982) and was supplemen ed by he model o Izaola e al.
(2007). Bo h models use modula ion unc ions o de ine he occupancy o Fe si es, bu he
Izaola model uses disc e e occupancies (i.e., an a om is ei he p esen o no ) ins ead o
s a is ical ep esen a ions (p obabili y o an a om being p esen ). This acili a es an elegan
ep esen a ion o many possible laye s acking combina ions (pe iodic and ape iodic) in
one concise model. Howe e , like con en ional c ys allog aphic models, also he
supe space app oach ep esen a e aged and idealized s uc u es “condensed” in o a uni
cell and does no pa icula ly speci y he na u e o s ochas ically occu ing aul s o
de ec s ha may con ibu e o he eal s uc u al makeup.
As men ioned be o e, he laye s acking in py ho i e is always hexagonal wi h espec
o he sul u a oms, and hence he many possible s acking a ian s a e basically di e en
a angemen s o he Fe si e acancies wi hin he oc ahed al amewo k o he ixed sul u
la ice. This is a undamen al di e ence o he ZnS poly ypes, whe e he s uc u al
di e si y is con ibu ed by s acking a ia ions and aul s o he sul u laye s (i.e., singula
o epea ed swi ching be ween cubic and hexagonal s acking). Sugges ions ha e been
17
CHAPTER 1 INTRODUCTION
made o desc ibe py ho i e s uc u es by in oking plana c ys allog aphic de ec s known
as an i-phase bounda ies (APBs; Pie ce and Buseck 1974; Nakazawa e al. 1975; Ko o and
Ki amu a 1981), which esul om ansla ional displacemen s o Fe si e acancies wi hin
he sul u la ice (hence, hey a e ansla ion in e aces as opposed o o a ional wins, c .
Fig. 2-2 in Chap e 2). These de ec s in oduce some deg ee o diso de o he py ho i e
s uc u e, because, unlike he e y s a ic s acking aul s in he sul u la ice, hey can mo e
qui e eely h ough he c ys al by jumping o Fe a oms be ween illed and acan la ice
posi ions, which e ec i ely shi s he acancies and equi es ela i ely li le ac i a ion
ene gy (compa ed o shi ing sul u a oms, Condi e al. 1974).
In p inciple, he e a e h ee s a es o diso de o be ecognized: (i) Vacancies a e
comple ely diso de ed wi hou any sho - ange in e ac ion. APBs canno exis and he
s uc u e is pu ely s ochas ic. (ii) Vacancies and APBs a e pe ec ly long- ange o de ed.
This is analogous o idealis ic laye s acking models, and APBs a e in insic s uc u al
elemen s and no de ec s sensu s ico. (iii) In-be ween he wo cases acancies a e o de ed,
bu APBs a e no s ic ly con ined and cause a iable deg ees o diso de by being
i egula on mesoscopic leng h scales much la ge han he in e a omic dis ances (e.g., by
being wa y). In Chap e 2 we p esen e idence o he la e case in py ho i e.
1.1.3. Py ho i e in Ea h and Plane a y Ma e ials
Magma ic py ho i e is a p ima y phase in unal e ed basal ic ocks (Hall 1986) and
o en occu s closely associa ed wi h Ni- and Cu-bea ing Fe sul ides. Down o
empe a u es o abou 260 o 300 °C a comple e solid solu ion se ies exis s be ween me al-
de icien Fe1-xS and Ni1-xS and is known as monosul ide solid solu ion (MSS; C aig 1973;
Mis a and Flee 1973). Pen landi e, (Fe,Ni)9S8, p ecipi a es om MSS below 610 °C
(Kulle ud 1963; Nald e e al. 1967), bu may also o m h ough in e sion o a high
empe a u e pen landi e o m (Sugaki and Ki akaze 1998). The addi ion o Cu o he
sys em adds u he complexi ies (Flee and Pan 1994; Flee 2006). Consequen ly, he
mine al pa ageneses o med in high- empe a u e magma ic sul ide deposi s and sul ide
d ople s in gabb os and basal s, can be a he ich asso men s o sul ide mine als,
al hough py ho i e and pen landi e usually domina e (e.g., P icha d e al. 2004). Mos ly
simple py ho i e-bea ing assemblages a e equen ly ound in many silicic magma ic
ocks (e.g., Whi ney 1984).
Hyd o he mally o med py ho i e occu s, al hough mos ly subo dina e o py i e (FeS2),
18
CHAPTER 1 INTRODUCTION
in polyme allic olcanic-hos ed massi e sul ide (VMS) and shale-hos ed/ sedimen a y
exhala i e (SEDEX) deposi s, whe e i o med om ho , me al-laden solu ions in
subma ine en i onmen s (e.g., Ohmo o 1996; Saéz e al. 2011). I s mode n p ecipi a ion
and deposi ion as µm-sized c ys als om he black plumes o deep sea ‘black smoke ’
en s is well documen ed (Con e se e al. 1984; He zig and Hanning on 1995). In
epigene ic hyd o he mal sys ems and me asoma ic o e deposi s py ho i e can occu
locally in abundance, bu only i condi ions a e su icien ly educing o p e en o ma ion
o py i e o oxidized sul u species (Hall 1986).
Py ho i e occu s in sedimen a y en i onmen s, bu i s o en p oposed o ma ion du ing
ea ly diagenesis has been challenged and mos py ho i e is likely o de i al o igin (Ho ng
and Robe s 2006). F om a physicochemical poin o iew py ho i e o ma ion in low-
empe a u e, educed sedimen a y en i onmen s is unlikely e en unde he mos a o able
condi ions (Hall 1986; Ho ng and Robe s 2006). Ins ead, py i e and o he monosul ide
phases such as mackinawi e ( e agonal FeS), g eigi e (Fe3S4), and possibly smyhi e
(Fe9S11) o m (Ricka d and Lu he 2007).
In me amo phic ocks, he s abili y o py ho i e ela i e o py i e is p ima ily
de e mined by empe a u e and he edox s a e, namely by he ugaci ies o oxygen ( O2)
and sul u ( S2), which a e hemsel es con olled by luid anspo (i.e., H2S emo al),
bu e ing mine al assemblages, and he con en o ca bonaceous ma e (Hall 1986).
Py ho i e and MSS a e known om a a ie y o ocks om Ea h’s uppe man le, which
a e accessible as xenoli hs in basal ic and kimbe li ic/lamp oi ic olcanic ocks (e.g., de
Waal and Calk 1975; Tsai e al. 1979; Shaw 1997). The e y edox-sensi i e
he mochemis y o py ho i e/MSS has been used o in e O2 and S2 o he li hosphe ic
man le using he equilib ium wi h ayali e and e osili e componen s in coexis ing oli ine
and o hopy oxene (Eggle and Lo and 1993; Fig. 1-3). Py ho i e as pa o exsol ed
MSS equen ly occu s as inclusions in man le-de i ed diamonds (Sha p 1966; Taylo and
Liu 2009) and could be used as a physical geoba ome e based on i s p essu e-dependen
magne ic p ope ies (Clemen e al. 2008; Gilde e al. 2011).
In ex a e es ial ma e ials, oili e (s oichiome ic FeS) occu s ex ensi ely in almos
all classes o me eo i es (Rubin 1997). Non-s oichiome ic py ho i e (+pen landi e) is
p esen se e al chond i ic me eo i e g oups, pa icula ly in he ca bonaceous CI, CM, and
CK chond i es and he Rumu u i g oup (Ke idge 1976; Ke idge e al. 1979a,b;
19
CHAPTER 1 INTRODUCTION
Kallemeyn e al. 1991; Geige and Bischo 1995; Rubin and Kallemeyn 1989; Schulze e
al. 1994), in in e plane a y dus pa icles (IDPs; Zolensky and Thomas 1995; Dai and
B adley 2001), and in samples o come 81P/Wild 2 e u ned by NASA’s S a dus mission
(Be ge e al. 2011).
FIGURE 1-3. The mochemis y o py ho i e (a 1ba ). The composi ion o py ho i e a high
empe a u es depends on S2 and T, shown as isople hs o x alues in Fe1-xS (g ay, Toulmin and
Ba on 1964; Rau 1976). The py ho i e s abili y ield is bounded by eac ions o ming i on (low
S2) and py i e (high S2). Py ho i e can unde go eac ions wi h oxides and hese can be used o
o mula e S2 bu e s, exempla ily shown o he ayali e-magne i e-qua z-py ho i e
(Fa+Mag+Qz+Po) bu e ( ed dashed line, a e Eggle and Lo and 1993). The bu e cu e esul s
om he in e sec ion o equi alen O2 isoba s ha ela e o wo basic eac ions: Fe2O3 (Mag) + S2
↔ 2FeS (Po) + 1.5O2 (blue isoba s) and Fe2SiO4 (Fa) + S2 ↔ 2FeS (Po) + SiO2 (Qz) + O2 (g een
isoba s). The isoba s a e de i ed by ela ing he ac i i y o FeS in Fe1-xS o gi en eac ion,
empe a u e, and O2 o he x alue and S2 using he ela ions o Toulmin and Ba on (1964) and
Rau (1976).
These ma e ials da e back o he ea ly Sola Sys em abou 4.56 Ga ago when he
collapse o an in e s ella molecula cloud (i.e., a as egion o enhanced gas and dus
densi y) led o he o ma ion o he p o o-Sun and an en elope and la e encompassing
disk-like body o dense gas and dus , known as he sola nebula o p o oplane a y disk
(Alexande e al. 2001; Boss 2003). Thei p ima y componen s o med by e apo a ion and
condensa ion o dus in exchange wi h a gas phase o app oxima e sola composi ion and
20
CHAPTER 1 INTRODUCTION
we e p ocessed in he complexly e ol ing disk en i onmen , which expe ienced mul iple
hea ing e en s and ex ensi e anspo and mixing o deba ed o igin (e.g., K o e al.
2009). These p ocesses led o he o ma ion o coa se-g ained, up o mm-sized objec s
(e.g., Mg,Fe silica e sphe ules o ‘chond ules’, he namesakes o ‘chond i es’) ha
acc e ed o o m plane esimal bodies (Chiang and Youdin 2010). The ma e ials named
abo e a e conside ed ‘p imi i e’, because hey ha e ne e been subjec ed o mel ing and
di e en ia ion in hei pa en plane esimal bodies. Howe e , many o hese bodies
expe ienced seconda y e ec s by hyd o he mal al e a ion (B ea ley 2006), sub-solidus
he mal me amo phism (Huss e al. 2006), o impac - ela ed shock me amo phism and
b eccia ion (Bischo and S ö le 1992). Dis inguishing inge p in s o hese p ocesses
a e di icul o cons ain and Chap e 3 goes in o de ail abou hese p oblems.
Py ho i e appea s o be ela i ely a e in me eo i es ha o med as p oduc s o esidues
o pa ial mel ing and mel seg ega ion (‘achond i es’, lacking chond ules). Howe e ,
py ho i e is well documen ed in achond i es o he she go i e-nakhli e-chassigni e (SNC)
g oup (Roche e e al. 2001; Lo and e al. 2005; Che ie e al. 2011), which bea
esemblance o e es ial basal s and ul ama ic ocks and o igina ed on Ma s (T eiman e
al. 2000). The possibly widesp ead dis ibu ion o py ho i e on he su ace o Ma s migh
ela e o obse ed magne ic anomalies (Roche e e al. 2001), and some e idence sugges s
ha py ho i e and silica es we e subjec ed o al e a ion o wea he ing p ocesses while s ill
esiding on Ma s (T eiman 2005; Che ie e al. 2011).
1.1.4. Oxida ion and Dissolu ion o Py ho i e
Albei py ho i e occu s occasionally abundan ly in many o e deposi s, i s own
economic alue is p ac ically nil and commonly i s associa ed phases, like pen landi e, a e
he main ocus o mining and mine al p ocessing (e.g, Becke e al. 2010). In o de o
educe en i onmen ally de imen al SO2 emission om smel ing p ocesses, mine al
p ocessing aims a enhancing he aluable phases and educing he py ho i e con en in
he o e concen a es. Because he magne ic beha io o py ho i e a ies ex ensi ely (e.g.,
Schwa z and Vaughan 1972) magne ic sepa a ion is di icul o apply and commonly
lo a ion is he me hod o choice in p ocessing o py ho i e bea ing o es. Flo a ion
exploi s he in insic o induced hyd ophobic su ace p ope ies o mine als o sepa a e
hem in s eams o ai bubbles passing h ough a mine al suspension in wa e (e.g.,
Fue s enau e al. 2007). Py ho i e can ha e sel -induced o in insically hyd ophobic
21

CHAPTER 1 INTRODUCTION
su aces (Buckley and Riley 1991) and, in p inciple, could be sepa a ed om hyd ophilic
mine als wi h educed applica ion o expensi e and en i onmen ally p oblema ic
su ac an s (‘collec o s’) used modi y he g ain’s su ace p ope ies. Howe e , oxida ion o
py ho i e su aces and he o ma ion o hyd ophilic Fe oxyhyd oxide laye s can
signi ican ly impai he e iciency o lo a ion and s udies ha e shown ha di e en ypes
o py ho i e ha e dis inc suscep ibili ies o su ace oxida ion du ing p ocessing (Ekmekçi
e al. 2010; Becke e al. 2010).
Once economically ba en sul ides ha e been sepa a ed om he o e, hey a e usually
s o ed in ailings eposi o ies o used o e ill mine wo kings. Simila ly, py i e- and
py ho i e-bea ing was e ock om mining ac i i y is dumped o used as back ill. Bo h in
su ace and unde g ound se ings, sul ides exposed o oxygen-con aining su ace wa e s
s a o oxidize. As de ailed in Chap e 4 o py ho i e, he wea he ing p ocess can lead o
he p oduc ion o acid and he consequen ial dec eases o he pH o e luen mine wa e s.
This p oblem is known as ‘acid mine d ainage’ (AMD) o ‘acid ock d ainage’ (ARD; i
un ela ed o mining) and has s imula ed in ensi e esea ch in he ecen yea s (e.g., Jambo
e al. 2003; Hudson-Edwa ds e al. 2011), because such wa e s can ha e emendous
en i onmen al and economic impac s by dis up ing i e ine ecosys ems (e.g., G ay 1997;
G ay and Delaney 2010) and anspo ing oxic me als and semi-me als (e.g., Ni, Cu, As)
in hei mobile, dissol ed s a e (e.g., Cheng 2008 e al; No ds om 2011), capable o
endange ing human heal h.
Resea ch has ocused bo h on he gene a ion o AMD and he mi iga ion and
emedia ion o i s e ec s (e.g., Johnson and Hallbe g 2005; Lo e mose 2011) and he eby
much a en ion has concen a ed on he wea he ing o py i e, undoub edly he mos
common sou ce o AMD. Howe e , he con ibu ion o py ho i e o AMD can be
signi ican (e.g., Belzile e al. 2004; Moncu e al. 2009; Jamieson 2011), and i is known
ha he a es o oxida ion and dissolu ion o py ho i e can exceed hose o py i e by
ac o s o 20 o 100 (Nicholson and Scha e 1994). Resea ch o he pas decades has also
shown ha mic obiological in e ac ions play a signi ican ole in enhancing he wea he ing
a es o Fe sul ides (e.g., Johnson and Hallbe g 2003; Hallbe g 2010). Hence, he
knowledge o he in insic physicochemical p ope ies o py ho i es, as de ailed in
Chap e 4, is impo an o p edic he mine al’s beha io in mining en i onmen s and
mine al p ocessing and se es as impo an benchma k o he e alua ion o how
mic oo ganisms a ec wea he ing p ocesses. Aside om mining en i onmen s his
22
CHAPTER 1 INTRODUCTION
unde s anding is o gene al in e es in he ligh o g owing ecogni ion o Ea h’s ‘c i ical
zone’, whe e ocks in e ac wi h he a mosphe e, hyd osphe e, and biosphe e (e.g.,
Ande son e al. 2007). The occu ence o py ho i e no only in e es ial ocks bu also in
chond i es and pa icula ly on he su ace o Ma s (sec ion 1.1.3) ende s py ho i e’s
al e a ion beha io in e es ing o he unde s anding o wa e - ock in e ac ions in
as e oidal (o come a y) bodies and he e olu ion o he ‘c i ical zone’ on plane a y
su aces.
1.2. No el and Specialized Me hods
This sec ion se es o explain some o he newe o mo e unusual echniques deployed
in he esea ch p esen ed in his disse a ion. Ope a ion de ails on hese and he
con en ional me hods used a e p o ided in he espec i e chap e s.
1.2.1. Focused Ion Beam P epa a ion
In he ecen yea s ocused ion beam (FIB) mic oscopes ha e become widely a ailable
in ma e ial sciences (Volke and Mino 2007) and ind inc easing applica ion in Ea h and
plane a y sciences (e.g., Heaney e al. 2001; Lee e al. 2003; Zega e al. 2007). The
wo king p inciple o a FIB mic oscope is compa able o a con en ional scanning elec on
mic oscope (SEM). Ins ead o an elec on sou ce, a liquid me al ion sou ce (LMIS) is
used, which commonly in okes gallium due o i s low mel ing poin (~30 °C) and low
apo p essu e (Volke and Mino 2007). Wi hin he LMIS, gallium o ms a hin ilm on a
sha p me al ip and Ga+ ions a e ex ac ed om his by ield emission h ough applica ion
o a high ex ac ion ol age. The ions a e hen accele a ed ( ypically o 2−30 keV) and
ocused by elec os a ic lenses in o a na ow beam, which scans he sample su ace
analogously o an SEM. Simila ly o a high ene gy elec on beam, he impac o ion
p oduces seconda y elec ons ha can be de ec ed o o m images. In mode n FIB
mic oscopes he physically limi ed la e al image esolu ion can each abou 10 nm
(Volke and Mino 2007).
Unlike SEM, FIB mic oscopy is inhe en ly damaging o he sample, because he la ge
size and momen um o impac ing ions leads o ejec ion (‘spu e ing’) o he sample’s
a oms. Howe e , his e ec has been made ad an ageous use o by combining he high
esolu ion, con ollabili y, and spu e ing e iciency o FIBs o do mic oscale machining
on sample su aces. One pa icula ly impo an de elopmen is he capabili y o p epa ing
23
CHAPTER 1 INTRODUCTION
<100 nm hin lamellae o TEM s udies wi h e y high spa ial selec i i y. TEM samples
can be ob ained om egions as small as 10×10 µm wi hou damaging he su ounding
ma e ial (Fig. 1-4). This is pa icula ly use ul o a ge sca ce o locally e y con ined
ea u es ha would be nea ly impossible o p epa e by con en ional me hods (e.g., ion
milling, ul amic o omy).
FIGURE 1-4. FIB sample p epa a ion o TEM (SEM seconda y elec on images). (a) A
pla inum s ip is deposi ed on he si e o in e es . (b) The su ounding ma e ial on ei he side o
he in ended TEM lamella is spu e ed away by he ion beam. (c) The lamella is educed in
hickness (~ 0.5 µm), cleaned, and cu ee by he ion beam. Only one a aching poin emains
(le side). (d) A ungs en needle mic omanipula o is welded o he lamella by pla inum
deposi ion. The emaining a aching poin is spu e ed away and he lamella is ex ac ed. (e) The
lamella is a ached o he pos o a TEM g id by pla inum deposi ion and he ip o ungs en needle
is cu o . ( ) The lamella is hen hinned o inal, elec on- anspa en hickness (< 100 nm
ideally) by use o he ion beam.
Commonly, mode n FIB sys ems consis o a ‘dual beam’ a angemen , which
combines an SEM column wi h an inclined FIB column and allows moni o ing he sample
non-des uc i ely by elec ons while pe o ming mic omachining by ions. No ably,
mode n FIB p epa a ion is no only capable o emo ing ma e ial, bu also p o ides
addi ion o ma e ial ia ion-beam-assis ed chemical apo deposi ion, which se es o
p o ide p o ec ion and ‘glue’ o he p epa ed sample. Mos ly deployed is he deposi ion o
pla inum h ough injec ion o an o gano-me allic gas in o he acuum ha adso bs o he
sample su ace and is dissocia ed by he seconda y elec ons p oduced by he ion beam
(e.g., Pu e z and Swanson 1992). Ca e ul beam cu en con ol allows achie ing ne
24
CHAPTER 1 INTRODUCTION
g ow h o ma e ial ins ead o spu e ing, and, in p incipal, deposi ion can be
accommoda ed also by he elec on beam in o de o u he educe damage (albei a
much slowe deposi ion a e).
1.2.2. TEM Supe s uc u e Da k-Field Imaging
TEM da k- ield imaging is a powe ul
me hod o s udy s uc u al de ails,
pa icula ly de ec s, in c ys als. In b ie
(based on Williams and Ca e 2009), he
unc ioning p inciple o a TEM es s
upon an elec on beam in e ac ing wi h
he sample’s a oms h ough elas ic and
cohe en sca e ing. The inciden beam
can be equally desc ibed as a plane wa e
on , which in e ac s wi h he (quasi-
)pe iodically a anged elec os a ic
a omic po en ials o he hin specimen o
o m an in e e ence o di ac ion
pa e n in he back- ocal plane o he
objec i e lens (Fig. 1-5).
Di ac ion pa e ns ep esen sec ions
h ough he ecip ocal c ys al la ice
(basically ela ed o i s Fou ie -
ans o med elec on densi y) and can be
ei he p ojec ed on a sc een o ecombined in o eal images. In his p ocess, each
in e e ence maximum, co esponding o a B agg e lec ion o di ac ed beam, con ibu es
pa ial in o ma ion o he inal image, and commonly TEM employs ape u es o a iable
sizes placed in he objec i e’s back- ocal plane o con ol he speci ic con ibu ions.
FIGURE 1-5. P inciples o b igh - ield (BF)
and da k- ield (DF) TEM imaging (a e Williams
and Ca e 2009). In BF mode, he di ec beam
con ibu es p ima ily o he image. In DF mode,
he image is o med om a di ac ed beam. Bo h
images show he same egion o he sample, bu
he con as o he images di e s.
In b igh - ield (BF) mode he image is o med om he di ec beam (passing s aigh
h ough he sample wi hou di ac ion) and op ionally some o he di ac ed beams. In
da k- ield (DF) mode he image is o med om one o ( a ely) ew di ac ed beams.
Because each beam ca ies dis inc pa ial in o ma ion o he sample’s image, he DF
images ob ained om di e en beams show dis inc de ails. Such de ails can be o
25
CHAPTER 1 INTRODUCTION
c ys allog aphic aniso opy and su ace cha ge. A s ong change in kine ic beha io occu s
a a pH alue o 2.70 a 35 °C, which mos likely co esponds o he isoelec ic poin o
py ho i e su aces. The abundan o ma ion o elemen al sul u a pH alues below his
ansi ion poin s o incomple e oxida ion o sul ide and s eng hens he in e p e a ion ha
he a ailabili y o i on on he exposed su aces o py ho i e is he main con olling ac o
on a es o oxida i e dissolu ion. Abo e he ansi ion, no elemen al sul u p ecipi a es and
eac ion a es on p e iously eac i e su aces d op sha ply by almos wo o de s o
magni ude. Mos ema kably, e y p onounced, in insic eac i i y di e ences o +80 o
−50 % (depending on pH) exis among 4C- and NC-py ho i e. Because hei Fe/S a ios
di e only ma ginally, his is clea e idence ha APBs o igina ing om acancy o de ing
exe s ong con ol on chemical p ocesses a he mine al su ace. A key aspec in he
unde s anding o he eac i i y di e ences appea o be chains o ace-sha ing FeS6
oc ahed a, which occu in he py ho i e s uc u e and exhibi s ong axial elec onic
in e ac ions. These chains a e unca ed by Fe-si e acancies, bu a e longe in case o NC-
py ho i es, whe e non-conse a i e APBs add addi ional Fe a oms o he s uc u e. This
migh inc ease he eac i i y NC-py ho i e compa ed o 4C-py ho i e due o easie
in e ac ion be ween oxidan species and he Fe elec onic sys em. In acco dance wi h he
discussion in Chap e 2, hese ideas again exempli y ha he igid and modula laye
model o py ho i es may be inapp op ia e o desc ibe ealis ic py ho i e s uc u es and
hei bea ing on physicochemical p ope ies.
In conclusion, he combina ion o e idence om he h ee esea ch s udies
demons a es ha he complex and a iable c ys allog aphic eal s uc u es o py ho i e
co ela e wi h i s physicochemical p ope ies and beha io s. The s uc u al di e si y o
py ho i e is a key aspec o unde s and he pe ogene ic his o ies o py ho i e-bea ing
ocks as well as na u al and an h opogenically induced wea he ing p ocesses. Pa icula ly,
u u e s udies o he complex magne ic p ope ies o py ho i e and py ho i e-bea ing
ocks and o he ye poo ly unde s ood s uc u e modi ica ions o py ho i e a
in e media e empe a u es be ween abou 200 o 320 °C could bene i om he e idence
and models p esen ed in his hesis.
32

CHAPTER 1 INTRODUCTION
1.4. Au ho Con ibu ions
In Chap e s 2 and 4, D . Kilian Pollok (K.P.) and P o . D . Falko Langenho s a e co-
au ho s o he published o submi ed esea ch a icles. In Chap e 3 F.L. is co-au ho o
he submi ed a icle. K.P. concei ed and p oposed he p ojec o s udy he in luence o
mic os uc u es on he wea he ing beha io o monosul ides and conduc basic esea ch on
he eal s uc u es o na u al py ho i es. F.L. sugges ed o s udy mic os uc u es and
al e a ion p ocesses in me eo i ic py ho i es. Bo h suppo ed he esea ch and con ibu ed
aluable expe ise, pa icula ly in TEM wo k. I selec ed all samples, ca ied ou all
analy ical cha ac e iza ion, and p ocessed and e alua ed he analy ical da a. I concei ed
and designed he expe imen s o Chap e 4, acqui ed he expe imen al and analy ical da a,
and p ocessed and e alua ed hem. I in e p e ed he da a and de eloped he ideas and
concep s p esen ed in Chap e s 2, 3, and 4. I w o e he manusc ip s ep oduced he ein and
c ea ed all igu es. The manusc ip s inco po a e aluable commen s and sugges ions by
K.P. and F.L. Chap e 2 inco po a es sugges ions om e iews by P o . D . Allan P ing
and an anonymous e iewe . In summa y, I con ibu ed a leas 90 % o he wo k and
concep s p esen ed in Chap e s 2, 3, and 4.
33
CHAPTER 1 INTRODUCTION
1.5. Publica ions Connec ed o This Disse a ion and Rela ed Wo k
A icles, Pee Re iewed and Published
Ha ies D., Pollok K., and Langenho s F. (2011) T ansla ion in e ace modula ion in
NC-py ho i es: Di ec imaging by TEM and a model owa d unde s anding pa ially
diso de ed s uc u al s a es. Ame ican Mine alogis 96, p. 716−731 (Chap e 2).
A icles, Submi ed and in Re iew
Ha ies D. and Langenho s F. (2012) The Nanoscale Mine alogy o Fe,Ni Sul ides in
P is ine and Me amo phosed CM- and CM/CI-like Chond i es: A emp ing o Tap a
Pe ogene ic Reco d. Submi ed o Me eo i ics and Plane a y Science on Decembe
12, 2011. (Chap e 3).
Ha ies D., Pollok K., and Langenho s F. (2012) Oxida i e dissolu ion o 4C- and NC-
py ho i e: In insic eac i i y di e ences, pH dependence, and he e ec o
aniso opy. Submi ed o Geochimica e Cosmochimica Ac a on Janua y 9, 2012.
(Chap e 4).
Con e ence Con ibu ions
Ha ies D., Be g T., Palme H., and Langenho s F. (2011) The a e o me als in he sola
nebula: F om condensa ion o oxida ion, sul ida ion, and ni ida ion. Wo kshop on
Fo ma ion o he Fi s Solids in he Sola Sys em (Kaua’i, USA), abs ac 9071.
(Pos e p esen a ion).
Ha ies D., Pollok K., and Langenho s F. (2011) Py ho i e oxida i e dissolu ion:
C ys allog aphic and mic os uc u al con ols obse ed by FIB-TEM and 3D
opome y. Join Mee ing o DGK, DMG and ÖMG (Salzbu g, Aus ia), abs ac
145.
Ha ies D., Pollok K., and Langenho s F. (2011) Py ho i e oxida i e dissolu ion: A
mic os uc u al pe spec i e by FIB-TEM and su ace opome y. 21s Annual V. M.
Goldschmid Con e ence (P ague, Czech Republic). Mine alogical Magazine 75, p.
980.
Ha ies D. and Langenho s F. (2011) Nanoc ys alline P-bea ing pen landi e and
ch omium ni ides om CM2 chond i es Y-791198 and Y-793321. 74 h Annual
Me eo i ical Socie y Mee ing 2011 (G eenwich, Uni ed Kingdom), abs ac 5165.
Ha ies D. and Langenho s F. (2011) Sul ides in CM and CM/CI-like chond i es and
hei eco d o he mal me amo phism: A FIB-TEM s udy. 74 h Annual Me eo i ical
Socie y Mee ing 2011 (G eenwich, Uni ed Kingdom), abs ac 5166.
Ha ies D., Fabian K., Pollok K., and McEn oe S.A. (2011) Co ela ion o
mic os uc u es and exsolu ion lamellae in na u al py ho i es and magne ic
p ope ies. EGU Gene al Assembly 2011 (Vienna, Aus ia), abs ac 12987.
Ha ies D., Be g T., Palme H., and Langenho s F. (2011) The s uc u e o e ac o y
me al alloys, condensa es om he ea ly sola nebula. 42nd Luna and Plane a y
Science Con e ence (The Woodlands, USA), abs ac 1837.
Mang Ch., Kon ny A.M., Ha ies D., Langenho s F., and Reimold, U. (2010) Shock
de o ma ion and nuclea ion o magne ic mine als in sue i es o he Chesapeake Bay
impac c a e , USA. AGU Fall Mee ing 2010 (San F ancisco, USA), abs ac
34
CHAPTER 1 INTRODUCTION
35
GP43B-1056.
Pollok K., Ha ies D., Hop J., E zel K., Chus T., Hochella M.F., Hellige K., Pei e S.,
and Langenho s F. (2010) Mic os uc u al con ols on monosul ide wea he ing and
hea y me al elease (MIMOS). Geo echnologien Science Repo No. 16, S a us
Semina 2010 (Mainz, Ge many), p. 182-197.
Ha ies D. and Langenho s F. (2010) A FIB-TEM s udy o sul ide mine alogies in CM
chond i es. Pane h Kolloqium 2010 (Nö dlingen, Ge many), abs ac olume.
Ha ies D., Pollok K., and Langenho s F. (2010) T ansla ion in e ace modula ion in
py ho i e: S uc u al sel -o ganisa ion obse ed by ansmission elec on
mic oscopy. 88 h Annual Mee ing o he DMG (Müns e , Ge many), abs ac
olume.
Pollok K., Chus T., and Ha ies D. (2010) F om su ace mo phology o a es: An
au oma ed ou ine o e alua e con e ged oughness pa ame e s o he e ogeneous
su aces. 88 h Annual Mee ing o he DMG (Müns e , Ge many), abs ac olume.
Ha ies D., Pollok K., and Langenho s F. (2010) Sel -o ganisa ion in he modula ed
s uc u e o py ho i e: Di ec obse a ions by TEM. 20 h Gene al Mee ing o he
IMA, (Budapes , Hunga y), abs ac olume p. 740.
Pollok K., Hop J., Ha ies D., Chus T., Hochella M.F., and Langenho s F. (2010)
Mic obially enhanced dissolu ion o py ho i e poly ypes: Su ace oughness,
eac i i y and a es. 20 h Gene al Mee ing o he IMA (Budapes , Hunga y), abs ac
olume, p. 381.
Ha ies D., Pollok K., and Langenho s F. (2009) Nanome e -wide magne i e lamellae in
mixed 4C/NC- ype py ho i e om Bodenmais (Ba a ia, Ge many) – al e a ion o
exsolu ion? 87 h Annual Mee ing o he DMG (Halle, Ge many). Hallesches
Jah buch ü Geowissenscha en 31, p. 94.
Ha ies D., Pollok K., and Langenho s F. (2009) Py ho i e, poly ypes and pH: A TEM
s udy on s uc u al complexi y and i s e ec s a he mine al- luid in e ace. MAPT
mee ing 2009 (Edinbu gh, Uni ed Kingdom), abs ac olume.
Ha ies D., Pollok K., E zel K., and Langenho s F. (2009) S uc u al Complexi y in
Py ho i es: Wha a e he implica ions o mine al wa e in e ac ions? 19 h Annual V.
M. Goldschmid Con e ence (Da os, Swi ze land). Geochimica e Cosmochimica
Ac a 73, Suppl. 1, abs ac A495.
Pollok K., Hellige K., Ha ies D., and Pei e S. (2009) Redox P ocesses a he
Nanoscale: A TEM Pe spec i e o I on Sul ide-I on (Oxyhyd )oxide Reac ions. 19 h
Annual V. M. Goldschmid Con e ence (Da os, Swi ze land) Geochimica e
Cosmochimica Ac a 73, Suppl. 1, abs ac A1039.
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
CHAPTER 2 T ansla ion In e ace Modula ion in NC-Py ho i e: Di ec Imaging by
TEM and a Model owa d Unde s anding Pa ially Diso de ed
S uc u al S a es
by Dennis Ha ies*, Kilian Pollok, and Falko Langenho s #
Baye isches Geoins i u , Uni e si y o Bay eu h, D-95440 Bay eu h,
Ge many. #P esen add ess: Ins i u ü Geowissenscha en, F ied ich-
Schille -Uni e si ä Jena, Bu gweg 11, D-07749 Jena, Ge many.
*Co esponding au ho . Email: dennis.ha ies@uni-bay eu h.de
2.1. Abs ac
The c ys allog aphic complexi y o ‘hexagonal’ o ‘in e media e’ py ho i es (Fe1-xS
wi h 0.125 > x > 0.080) is a long-s anding and challenging p oblem. In eg al (e.g., 5C) and
non-in eg al NC ype s uc u es ound wi hin his g oup a ambien empe a u es a e
cha ac e ized by sha p bu complica ed elec on di ac ion pa e ns, which we e ound o
be in e p e able in e ms o a ansla ion in e ace modula ion (TIM) supe s uc u e.
T ansmission elec on mic oscopy (TEM) da k- ield images ob ained using supe s uc u e
e lec ions show dense a angemen s o s ipes which can be in e p e ed as a ays o
closely spaced an i-phase domain bounda ies (APB). The displacemen ec o a he
in e ace is R = 1/8[001] o a me ically hexagonal 4C supe s uc u e cell and he in ol ed
ansla ions a e solely con ined o he Fe subla ice. The acancy a angemen o he APB-
ee monoclinic 4C-py ho i e se es as a base o he TIM supe s uc u e and he e o e NC
s uc u es can be ega ded as wo supe -imposed o de ing phenomena ela ing o he
a angemen s o indi idual acancies and APBs, espec i ely. APBs a e chemically non-
conse a i e and go e n he highe Fe/S a ios o in e media e NC-py ho i es. I o ien ed
s ic ly pa allel o (001) he APBs can be ega ded as comple ely illed Fe double laye s
wi hin he 4C s acking sequence. Howe e , di ec imaging o APBs shows wa iness and
a iable diso de on mesoscopic scales, yielding essen ially ape iodic s uc u es. A high
deg ee o sel -o ganiza ion among APBs has been obse ed wi hin appa en di usion
p o iles a ound exsol ed oili e lamellae and along in e aces wi h 4C-py ho i e, whe e
complica ed eigh - old node a angemen s occu . Ou TEM obse a ions indica e ha all
NC- ype py ho i es can be ea ed by he TIM app oach and ha he concep s o
poly ypism and polysoma ism in py ho i e a e no ully capable in ep esen ing he
obse ed s uc u al complexi ies.
36
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
2.2. In oduc ion
Py ho i e comes a close second a e py i e among he mos abundan i on sul ides in
o e deposi s and c us al ocks. I s NiAs-de i a i e s uc u e con ains sequences o
hexagonal close-packed S a om laye s s acked in al e na ion wi h laye s o Fe a oms in
oc ahed al coo dina ion. Non-s oichiome ic composi ions a ise om he p esence o
acancies wi hin Fe laye s and span he ange in-be ween ~47 o 50 a % Fe (Fe7S8 o FeS),
whe eas mos s uc u al complexi y occu s in he na ow composi ional ange be ween 47
o 48 a % Fe. A empe a u es below 300°C a ious supe s uc u es a e obse ed in his
ange due o acancy o de ing among and wi hin Fe laye s, esul ing in a a he
complica ed subsolidus phase diag am (Desbo ough and Ca pen e 1965; Kissin and Sco ,
1972; Kissin and Sco 1982; Nakazawa and Mo imo o 1970). A ecen e iew on
s uc u al and magne ic phase ansi ions is gi en by Wang and Sal eson (2005). A
ambien empe a u es he e a e h ee membe s o he py ho i e amily being ound in
na u e: oili e (2C-py ho i e, FeS, an i e omagne ic), 4C-py ho i e (Fe7S8,
e imagne ic) and NC-py ho i e (in-be ween FeS and Fe7S8, an i e omagne ic). He e
py ho i e p e ixes indica e he supe s uc u e la ice epea along he axis o laye s acking
ela i e o he c-axis pe iodici y o he NiAs subs uc u e (Mo imo o e al., 1970) and he
la e wo ypes co espond o he mo e adi ional ‘monoclinic’ and ‘hexagonal’ (o
‘in e media e’) py ho i e designa ions, espec i ely. Unlike he well known 2C and 4C
s uc u es he NC- ype py ho i es o m a s uc u ally di e se g oup wi h widely a iable
Nc alues among which he special cases Fe9S10 (5C), Fe11S12 (6C), and Fe10S11 (11C o
5.5C wi hou conside ing sul u laye s acking) ha e been p oposed as s able phases a
oom empe a u e (Mo imo o e al. 1970; Nakazawa and Mo imo o 1970). Besides hese
in eg al NC-py ho i es i is es ablished ha NC-py ho i es exis , in which he appa en
supe s uc u e pe iodici y is ela ed o he c-axis epea o he NiAs subs uc u e in a non-
in eg al manne . Repo ed Nc alues ange be ween 4.2 o 6.6 (Mo imo o e al. 1975a;
Mo imo o e al. 1975b; Pós ai e al. 2000; Yamamo o and Nakazawa 1982). O e he las
decades he s abili y ela ions o in eg al and non-in eg al supe s uc u es ha e been a
ma e o deba e, al hough i seems ha s udies p e e en ially ocussed on he s uc u al
and physical p ope ies o he in eg al ypes. Alongside concep ual p oblems ega ding he
c ys allog aphic desc ip ion o non-in eg al supe s uc u es, obse a ions on syn he ic and
na u al py ho i es a ambien empe a u es ace di icul ies due o slow o de ing kine ics,
p onounced phase he e ogenei y, and a high, bu o en sub le, a iabili y o di ac ion
37

CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
da a, demanding ca e ul e alua ion. Py ho i e shows excessi ely a iable magne ic and
physicochemical p ope ies (Wang and Sal eson 2005) and occu s widesp ead in ocks
and o e deposi s. Realis ic s uc u al models a e equi ed o concei e he na u e o
magne ic p ope ies and phase ansi ions and a e c ucial o unde s and p ocesses on
mine al su aces. A p ominen example is lo a ion p ocessing, whe e d as ic di e ences in
e iciency ha e been demons a ed o magne ic and non-magne ic py ho i es (Becke e
al. 2010).
The monoclinic 4C-py ho i e is
wi hou doub he bes cha ac e ized and
unde s ood py ho i e supe s uc u e
(Be au 1953; Tokonami e al. 1972;
Powell e al. 2004). Based on a NiAs-
ype s uc u e o FeS, he 4C s uc u e is
de i ed by emo ing 1/4 o Fe a oms
om e e y second Fe laye , leading o
he composi ion Fe7S8. Wi hin acancy-
bea ing laye s he Fe a oms a ange in
plana kagome la ices, o which ou
a ian s (VA, VB, VC, VD; Fig. 2-1a) a e
mu ually disce nible in he s acked
a angemen . The kagome a angemen
go e ns equal spacings be ween
neighbo ing acancies while a oiding
di ec neighbo ship by su ounding each
acancy by six Fe a oms. The esul ing
sequence o pa ially acan (V) and
illed (F) Fe laye s is VAFVBFVCFVDF;
i is cha ac e ized by s ic al e na ion o
V and F laye s. The spacing be ween V
laye s o he same ype is s ic ly ou
imes he c-axis epea o he NiAs
subs uc u e (o eigh Fe laye s; he possible pe mu a ions o he ABCD sequence a e
equi alen and ela e o di e en choices o he e e ence ame/coo dina e sys em).
FIGURE 2-1. (a) Schema ic ep esen a ion o
he p incipal laye ypes in he ideal s uc u es o
4C- and NC-py ho i es. F: illed Fe laye , V:
pa ially acan Fe laye in ou mu ually di e en
se ings (VA, VB, VC, VD), S: sul u laye s in
wo mu ually di e en se ings (S1, S2) o he hcp
s acking. (b) Basal iew o di e en py ho i e
uni -cell se ings (1H, 1O, 4M, 4H) wi h
indica ions o Fe si e posi ions. No e ha he
o iginal 4M cell o 4C-py ho i e as desc ibed by
Be au (1953) is o easons o cen e ing shi ed
wi h espec o he Fe posi ions.
38
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
S uc u al desc ip ions o in eg al NC-py ho i e s uc u es can be oughly di ided in o
wo app oaches using ei he disc e e (ze o o one) o pa ial Fe si e occupancies. The
o me ela es o an idealized ex ension o he 4C s acking scheme by in oducing
addi ional F laye s o s acking o ce ain building blocks, which inc eases bo h he
pe iodici ies o he supe s uc u es as well as he Fe/S a ios (Co le 1968; Dódony and
Pós ai 1990; Pós ai and Dódony 1990; Vaughan 1971). These concep s can be iewed in
e ms o a poly ypic o polysoma ic se ies. The addi ional in oduc ion o pa ial (i.e.,
s a is ical) si e occupancies implies a conside able diso de o Fe acancies (de Villie s
and Liles 2010; de Villie s e al. 2009; Ellio 2010; Ko o e al. 1975), whe eas he na u e
o his diso de is usually no add essed.
The p oblem o non-in eg al py ho i es was i s add essed by Pie ce and Buseck
(1974) who sugges ed a diso de ed a angemen o an i-phase domains anging in size
be ween one o h ee uni cells o he subs uc u e. Despi e being able o closely ep oduce
expe imen al di ac ion pa e ns, only ew de ails on he na u e and o de ing o domains
we e gi en and he ela ionship o composi ional a ia ions was no add essed. Ko o and
Ki amu a (1981) p oposed a somewha simila model in ol ing a o malism o wo ‘ou -
o -s ep’ ec o s lying in he ab-plane.
In con as o hese de ec - ela ed models Yamamo o and Nakazawa (1982) de eloped a
supe s uc u e desc ip ion o an Nc = 5.54 py ho i e based on a con inuous modula ion o
(pa ial) Fe si e occupancies. In his model o an ape iodic c ys al s uc u e he p obabili y
o inding a Fe a om a a gi en la ice si e is go e ned by a con inuous, sinusoid-like
modula ion unc ion embedded in a ou -dimensional supe space o malism. Ape iodici y
esul s om he occupa ion modula ion being incommensu a ely ela ed o he
subs uc u e pe iodici y. Based on his wo k Izaola e al. (2007) in oduced a gene alized
supe space app oach by eplacing he con inuous occupancy modula ion wi h a s ep-like
unc ion go e ning disc e e si e occupancies. By i ue o a ‘closeness’ condi ion, he
model s ic ly obeys he sequence o ABCD laye ing as well as he ule ha wo V laye s
mus no ollow consecu i ely wi hou an in e jacen F laye , esul ing in he ixed ela ion
1/Nc = 2x be ween supe s uc u e Nc alue and composi ion exp essed as x in Fe1-xS.
Depending on he Nc alue being a ional o i a ional he model will ei he p oduce
pe iodic/commensu a e s uc u es, including 4C and in eg al NC, o yield
ape iodic/incommensu a e laye sequences, espec i ely. These can be unde s ood as
uni o m s acks o V and F laye s in which ce ain pa e ns ecu bu a e aul ed by
39
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
de e minis ic, ye non-pe iodic inse ions o ex a laye s. Because such uni o m s uc u es
a e expec ed o yield sha p B agg di ac ion maxima (Amelinckx and an Dyck 1993),
hey can be conside ed as being quasi-pe iodic (Bu ows and Suls on 1991).
A p ima y mo i a ion o his s udy was ha he epo ed elec on di ac ion pa e ns
o non-in eg al NC-py ho i es s ongly esemble hose seen in ce ain modula ed bina y
alloys (Amelinckx and an Dyck 1993; B oddin e al. 1990). In hese alloy sys ems
p ima y in eg al supe s uc u es a ise in s oichiome ic compounds (e.g., Au3Zn) om
o de ing a oms on ce ain si es o he cc la ice. Non-s oichiome ic composi ions (e.g.,
Au3+xZn1-x) and seconda y supe s uc u es a e ela ed o addi ional o de ing phenomena
which can be desc ibed as egula a angemen o 2-dimensional de ec s o in e aces
wi hin he simple p ima y supe s uc u es. This egula a angemen is a s uc u al
modula ion. Speci ically, non-conse a i e (‘composi ion-changing’) an i-phase bounda y
(APB) in e aces can be made esponsible o a close coupling be ween he esul ing
seconda y supe s uc u es and concu en non-s oichiome y. In hese cases o APB
modula ed seconda y supe s uc u es, di ac ion pa e ns a e cha ac e ized by
eplacemen (o spli ing) o he p ima y supe s uc u e e lec ions wi h a ays o sa elli e
spo s. In analogy, he NC di ac ion pa e n could be ega ded as ep esen a i e o a
p ima y NiAs based supe s uc u e, which is modula ed by non-conse a i e APBs ha
lead o inc eased Fe/S a ios and he spli ing o 4C e lec ions in o he a ays o sa elli e
spo s seen in he NC di ac ion pa e ns. Figu e 2-2 se es o illus a e he di e ences in
2-dimensional de ec s, namely s acking aul s, APBs, and win bounda ies, in a py ho i e-
like ma e ial. S acking aul s and APBs a e cha ac e ized by b eaking he ansla ion
symme y o a c ys al and esul in a phase shi along he, so called, ansla ion in e ace.
In con as , win bounda ies a e cha ac e ized by a o a ion ins ead o a ansla ion. APBs
a e well known o be e y dynamical de ec s ha can ela i ely easily mo e h ough
c ys als and a ange in complex pa e ns (e.g., Van Tendeloo e al. 1974).
A success ul app oach owa ds he a ionaliza ion o modula ion by in e aces has been
in oduced by Fujiwa a (1957) and has la e been ex ended o he concep s o
c ys allog aphic shea (CS) s uc u es and ansla ion in e ace modula ion (TIM) by an
Landuy e al. (1970) and an Dyck e al. (1987). The CS concep was success ully applied
o many non-s oichiome ic ansi ion me al oxides (Ande sson and Wadsley 1966) and is
closely ela ed o TIM because CS planes (o Wadsley de ec s) can be ega ded as non-
conse a i e APBs ( an Landuy 1974).
40
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
FIGURE 2-2. Types o de ec in e aces pe pendicula o c in a py ho i e-like ma e ial (no e
ha only a simpli ied laye s acking and ene ge ically a o able con igu a ions a e shown). (a)
S acking aul : The whole la ice is ansla ed pe pendicula o he in e ace by he displacemen
ec o R and he gap is illed. A Fe double laye and a aul in he sul u laye s acking sequence
esul s. The Fe/S a io is changed. (b) Non-conse a i e an i-phase bounda y: Only he Fe
subla ice is ansla ed by R pe pendicula o he in e ace. A Fe double laye esul s bu he sul u
subla ice is le in ac . The Fe/S a io is changed. (c) Conse a i e an i-phase bounda y: The
whole la ice is ansla ed by R pa allel o he in e ace. All acancy laye ypes change and he
sul u subla ice is le in ac . The Fe/S a io is p ese ed. (d) Twin bounda y: The whole la ice is
o a ed abou an axis pa allel o c. The acancy laye ypes change, bu he one on which he
o a ion axis is cen e ed emains he same. Depending on he angle he sul u subla ice is le
in ac (120°, shown) o aul ed (60°). The Fe/S a io emains unchanged.
The di e en s uc u al models discussed so a (poly ypic/polysoma ic laye s acking,
supe space embedmen , TIM) do no necessa ily ep esen di e en s uc u al s a es o
py ho i es bu a e a he di e en desc ip i e app oaches, which a y in hei capabili ies
o ep esen ing he eal s uc u es. The TIM app oach used in his s udy appea s
pa icula ly use ul o econcile he heo e ical ea men o di ac ion pa e ns and he
41
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
2.4.2.2. Geome ical Analysis o Di ac ion Pa e ns
TEM-SAED pa e ns ob ained om
lamellae in NYS and EUL ma ch he
di ac ion pa e n o 4C-py ho i e and
clea ly con i m he p esence o his phase as
exsolu ion p oduc in acco dance wi h
measu ed composi ions. Lamellae in he TYS
sample gi e sha p and unambiguous
di ac ion pa e ns o oili e, being also
compa ible wi h he measu ed composi ions.
Bo h 4C-py ho i e and oili e a e in
c ys allog aphic con inui y wi h hei
espec i e hos s, which a e shown by SAED
o be o he non-in eg al NC ype in all cases
(Fig. 2-4). This places hem be ween 4C-
py ho i e and oili e in ag eemen wi h
measu ed composi ions. By compa ison o
di ac ion pa e ns (Fig. 2-4) and de i ed Nc
alues (Tab. 2-1), i becomes appa en ha
NYS and EUL sha e besides e y simila
Fe/S a ios also e y simila s uc u al
pa ame e s wi h Nc being mos ly in he ange
o 4.8 o 4.9. Unlike EUL, NYS occasionally
shows s eaks and di use sa elli e di ac ion
maxima along he c* di ec ion. The la e
co espond o Nc alues being somewha
lowe han 4.8, bu quan i ica ion in hese cases is di icul due o con olu ion o di e en
di use sa elli es. The hos NC-py ho i e in TYS appea s mo e he e ogeneous wi h Nc
alues in he ange o 5.12 o 5.52, whe eas mos alues sca e closely a ound 5.5 when
oili e lamellae a e p esen nea by. Obse ed o de s m o sa elli e e lec ions gene ally
each e y high, up o 8 o 10, and oge he wi h mos ly sha p di ac ion spo s indica e
well o de ed s uc u es. Occasionally la e al shi s o e lec ions can be obse ed as shown
in Figu e 2-5a (also weakly in Fig. 2-4 ) and such di ac ion pa e ns can be indexed by
FIGURE 2-5. (a) TEM-SAED pa e n in
ZA [100]4H depic ing an o ien a ion anomaly
in he TYS sample wi h Nc = 5.13±0.01 and
N[120] app oxima ely 6 o 800, ela ing o
supe s uc u e e lec ions being shi ed
la e ally om hei ideal posi ions. (b)
Schema ic ep esen a ion o he SAED
pa e n. (c) De ail o (b) showing he ela ion
o q, qc, and q[u 0], which in his case is
o ien ed owa d [120]4H.
48

CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
allowing non-ze o q[u 0] componen s o q (Fig. 2-5b). These obse a ions sugges ha in
close analogy o he Au-Zn sys em he NC ype supe s uc u es in py ho i e a ise om
modula ed APBs modi ying he p ima y 4C supe s uc u e o med om acancy o de ing
in he NiAs subs uc u e – he NC s uc u es a e he e o e analogous o non-s oichiome ic
Au3+xZn1-x TIM supe s uc u es which a e supe posed on a p ima y supe s uc u e due o
simple o de ing o Au and Zn in he cc base la ice. Such an inse ion o non-conse a i e
APBs and o ma ion o a TIM supe s uc u e is capable o p oducing bo h in eg al and
non-in eg al NC ypes depending on he densi y and a angemen s o APBs. La e al
displacemen s o e lec ions ia non-ze o q[u 0] componen s a e hallma ks o TIM
s uc u es due o small sys ema ic inclina ions o APBs wi h espec o he hos la ice and
known as o ien a ion anomalies in alloy sys ems (Amelinckx and an Dyck 1993).
Inspec ing he schema ic di ac ion pa e ns in Figu es 2-4a,d,g show ha in gene al
sa elli e e lec ions only occu o subs uc u e e lec ions wi h l being a mul iple o 4. Fo
h + l = e en only sa elli es wi h m = e en, and con e sely o h + l = odd only sa elli es
wi h m = odd occu . As seen in Figu e 2-4d he indexing o supe s uc u e e lec ions in
he )10( l la ice ow is acili a ed by ela ing hem as sa elli es o he )10( l e lec ions
wi h l = 0,4,8,... by m imes q. These, gene ally absen , subs uc u e e lec ions (ma ked
by c osses) canno be indexed based on he con en ional monoclinic 4M cell o 4C-
py ho i e, hus necessi a ing a (pseudo-)hexagonal cell. The p ope 4C-py ho i e
e lec ions (open ci cles in Fig. 2-4a,d,g) can be ela ed o he sa elli es by a spli ing
ec o (o dis ance) q’. Fo example, inspec ion o Figu e 2-4g shows ha in zone axis
[210]4H he (0040) e lec ion o 4C-py ho i e is symme ically spli in o he sa elli es
)4008( and (0004), he dis ance be ween hem being q’. Fo he )2301( e lec ion o 4C-
py ho i e an asymme ic spli ing in o he )5281( and )2301( sa elli es occu s. The way
how e lec ions a e spli o how q’ is ela ed o he spli e lec ions can be desc ibed by a
ac ional shi Δ which is a mul iple o 1/8. Fo Δ = 0, q’ s a s a he spli e lec ion (i.e.,
sa elli e occu s a dis ance q’) and o Δ = 1/2 spli ing is symme ic. The p inciple is
applicable o all o he [u 0]4H zone axes as shown in Figu e 2-4, al hough spli ing is no
as ob ious, because i p oduces in e locking a ays o many sa elli es wi h high o de s.
The signi icance o q’ and ac ional shi s s ems om he ac ha in a TIM s uc u e he
in e se leng h o q’ di ec ly ela es o he a e age spacing o APBs and ac ional shi s
can be used o de e mine hei displacemen ec o R (Amelinckx and Van Dyck 1993;
49
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
an Dyck e al. 1987). Based on he pa e n geome ies, we ind ha o py ho i e q’
(desc ibing o ien a ion and spacing o APBs) and q (used o indexing sa elli es) can be
ela ed h ough he equa ion
q’ = 2c1H* − 8q.
Fo ypical Nc anges in ou samples o 4.80 o 4.90 (EUL/NYS) and 5.45 o 5.55
(TYS) we he e o e would heo e ically expec a e age APB spacings along he c di ec ion
o 1.74 o 1.58 nm and 1.09 o 0.96 nm, espec i ely. The ela ion o R and Δ is such ha
o a gi en subs uc u e e lec ion g (he e hose o he 4C s uc u e) g·R = Δ has o ag ee
wi h he obse ed ac ional shi s Δ. Using expe imen ally de e mined Δ, as indica ed in
Figu e 2-4, i can be shown ha only he ec o
R = 1/8[001]4H = 1/2[001]1H
is consis en wi h ou obse ed di ac ion pa e n geome ies. This ec o , i applied o a
illed Fe laye o he 4C s uc u e, p oduces a chemically non-conse a i e APB being
equi alen o wo consecu i ely illed Fe laye s. The con e se case o o ming wo
consecu i e acancy laye s appea s highly un a o able due o s ong epulsion be ween
he neighbo ing acancies. In gene al R = 1/8[001]4H is a alid APB displacemen ec o
only wi h espec o he Fe subla ice – i i is applied o an S laye a s acking aul in he
hcp subla ice would esul , which is no obse ed by TEM imaging, as we shall see.
Howe e , he sepa a e ea men o he Fe subla ice is legi ima e because supe s uc u es
solely a ise om he o de ing o Fe acancies.
2.4.3. Supe s uc u e Da k-Field Imaging (SDF-TEM)
In o de o ob ain SDF-TEM images om elec on beams di ac ed by he
supe s uc u e, i was ound o be mos e ec i e o place he objec i e ape u e on he
(0004) and )4008( sa elli e e lec ions accessed om nea he [210]4H zone axis (Fig. 2-6).
The sample oil was il ed such ha in he ideal case only di ac ed beams in he (00lm)
ecip ocal la ice ow we e exci ed.
In he NC po ions o bo h he EUL and NYS samples, SDF images e eal dense a ays
o da k s ipes being aligned pa allel o he (001) planes (Fig. 2-7a,b) and solely isible in
50
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
da k- ield images using s ong supe s uc u e e lec ions. In EUL he s ipes appea
sligh ly wa y on scales o a ew ens o nm along hei cou se. In compa ison, he s ipes
in NYS show much mo e wiggles and i egula i ies. Fu he , in NYS he con igu a ion o
s ipes appea s o change along ce ain domain bounda ies whe e he hin s ipes, as seen
in EUL, change in o hicke s ipes (a ows in Fig. 2-7b,d). The la e domina e he SDF
images o he NYS sample and a e likely double s o wo s ipes being oo close o be
esol ed unde he SDF imaging condi ions.
FIGURE 2-6. Di ac ion condi ions o SDF-TEM imaging as applied o he Nyse e (NYS),
S a. Eulalia (EUL), and Tys jo d (TYS) samples. The specimens a e il ed om he [210]4H zone
axis such ha di ac ed in ensi y is in he (00l) la ice ow. The dashed ci cle ep esen s he
diame e o he objec i e ape u e used o imaging, cen e ed on he (0040)4H e lec ion o he
subs uc u e. In non-in eg al NC-py ho i es his e lec ion is weak o ex inc , bu occasionally
occu s due o 4C domains wi hin he di ac ing olume.
The a e age spacing o s ipes in EUL is 1.63±0.05 nm and he obse ed (hal -)wid h
o a single s ipe is app ox. 0.80 nm. We measu ed he dis ances by di iding measu ed
in e als by he numbe o s ipes occu ing in hem (in e als usually 45–60 nm). The
a e age was ob ained om 16 measu emen s on eigh independen images. An al e na i e
de e mina ion by FFT ea men o a 400×400 nm2 a ea yielded a pe iodici y o 1.65±0.01,
which is in e y good ag eemen . Assuming he hick s ipes in NYS o be non- esol able
double s, he a e age spacing be ween indi idual s ipes is 1.94±0.10 nm (n = 15, six
images). A alue o 1.97±0.03 nm was ob ained om a 125×125 nm2 a ea o hin s ipes
ia FFT analysis and also ag ees e y well.
51
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
FIGURE 2-7. SDF-TEM images ob ained using he di ac ion condi ions shown in Fig. 2-6. (a)
Sample EUL showing pa allel and sligh ly undula ing APBs imaged as da k s ipes. (b) Sample
NYS showing hicke da k s ipes ha a e i esol able double s o wo APBs. A ows indica e
a eas in which s ipe con igu a ion is analogous o (a). Diso de o APB spacings and o ien a ions
is highe han in EUL. (c) Sample EUL. In e ace be ween NC- and 4C-py ho i e showing
e mina ion o APBs in eigh old node s uc u es. The beha io o APBs as double s is appa en .
(d) Sample NYS. In e ace be ween NC- and 4C-py ho i e showing he same ype o node
s uc u es as seen in EUL. A ows indica e changes in con igu a ion o APB double s. (e) Sample
EUL. In e ace be ween NC- and 4C-py ho i e subpa allel o (001). An eigh old node s uc u e is
seen wi hin he APB s ipes and he ou e mos APB double il s away in o he adjacen 4C-
py ho i e. ( ) Sample EUL. 4C lamella pa allel o (001) wi h a la ge block o APBs il ing away
om adjacen NC-py ho i e.
52
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
The a e age dis ance o EUL compa es e y well wi h he expec ed APB spacing as
ob ained om he SAED pa e n geome ies and we he e o e in e p e he da k s ipes o
be APBs. The ob ained SDF images s ikingly esemble o de ed APBs obse ed in Ni3Mo
by an Tendeloo e . al (1974). Based on con as in da k- ield images we can exclude he
s ipes o be s acking aul s o win bounda ies, as he o me would be seen wi h
subs uc u e e lec ions as well and he la e would show in ensi y di e ences o domains
on ei he si e o he bounda y. The la ge a e age spacing in NYS, despi e e y simila Nc
alues, is likely due o he highe diso de wi h la ge and mo e i egula spacings be ween
s ipes, which bias he mean dis ance o highe alues. No ably, he a e age o 1.94-1.97
nm co esponds o an Nc alue o app ox. 4.7, which is compa ible wi h di use sa elli e
e lec ions seen in SAED pa e ns ob ained a he imaging si es. This may imply some
locally inc eased diso de close o he exsolu ion lamellae which we e a ge ed o
imaging. Well de ined SAED pa e ns which we e conside ed o he calcula ion o
expec ed a e age spacing we e ob ained a he a away om 4C lamellae and showed no
con ibu ion o 4C e lec ions.
Mos s iking ea u es in SDF images o EUL and NYS a e he phase bounda ies
be ween 4C- and NC-py ho i e whe e he s ipes o m complica ed bu ema kably
simila node s uc u es in which he s ipes e mina e (Fig. 2-7c,d). When he phase
in e ace is o ien ed mos ly pa allel o he s ipes, no nodes occu di ec ly a he in e ace,
bu occasionally appea nea by wi hin he NC phase (Fig. 2-7e), o en associa ed wi h
disloca ions ha ing he appa en Bu ge s ec o b = [001]1H. In all cases o node s uc u es
we obse ed eigh s ipes o e mina e in a single node. Occasionally s ipes con inue in o
he 4C phase and il away om he ‘edge-on’ iew and blu ou o some ex en (Fig. 2-
7e, ). S ipes in he 4C po ion ha e been obse ed as singles, pai s, o la ge blocks o
mul iple s ipes (e.g., Fig. 2-7 ), bu i appea s ha he e is a s ong endency o s ipes o
o m double pai s as can be seen also in he bulk NC phases whe e he s ipes a e no
equally spaced.
The beha io o s ipes in he obse ed node s uc u es and adjacen 4C-py ho i e
s ongly endo ses ou in e p e a ion o hem being non-conse a i e APBs o he 4C
s uc u e. Thei o ien a ion is ully compa ible wi h he in e ed displacemen ec o R =
1/8[001]4H which c ea es double laye s o comple ely illed Fe posi ions as opposed o
single laye s being p esen in he 4C s uc u e. This is s ic ly ue i he APBs a e exac ly
no mal o he displacemen ec o , i.e., pa allel o (001). When he APBs a e wa y o
53

CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
inclined o he (001) plane he Fe excess associa ed wi h hem will be somewha less,
depending o he angle o inclina ion. In cases whe e he APBs a e pa allel o R, and hus
pe pendicula o he py ho i e laye s acking, no Fe excess will occu as he s uc u e is
jus shea ed by he leng h o R along he APB ‘ aul ’ plane. APBs wi h small bu
sys ema ic inclina ions o he (001) planes a e e y likely he explana ion o obse ed
o ien a ion anomalies (Fig. 2-5) analogous o anomalies seen in alloy sys ems (Amelinckx
and an Dyck, 1993). Also he obse ed nodes ind hei analogs in hese alloy sys ems
whe e hey a e known as ‘discommensu a ion nodes’ o ‘hai pin s uc u es’ (Sch y e s e
al., 1985; also well illus a ed in an Tendeloo e al., 1974). In ou case he eigh - old
nodes acili a e he econs uc ion o he 4C phases om he APB modula ed NC phase
and di ec ly suppo he p oposed displacemen ec o 1/8[001]4H as i s eigh - old mul iple
will be he c dimension o he 4C uni cell (see discussion sec ion). Appa en ly he highly
simila node con igu a ions ep esen a sel -o ganiza ion owa ds an ene ge ically op imal
phase in e ace.
FIGURE 2-8. SDF-TEM images o APB con igu a ions adjacen o oili e (T o) exsolu ion
lamellae in TYS py ho i e. Di ac ion condi ions as gi en in Fig. 2-6. (a) “Pape clip”-like APB
a angemen s wi hin a Fe-deple ed s anded di usion p o ile along he NC-T o in e ace. In
o ien a ions pe pendicula o (001) APBs il away om edge-on iew and s ipes appea blu ed.
(b) De ailed iew o APBs a he NC-T o in e ace. Wi h inc easing dis ance APB s ipes become
mo e and mo e pa allel o (001) and spacings na ow down.
Upon app oaching he in e aces o he oili e exsolu ion lamellae in he TYS sample
we we e able o image s ipes wi hin he NC phase displaying ben con igu a ions and
g adually inc easing spacings owa ds he phase bounda ies (Fig. 2-8). Simila o EUL and
NYS he s ipes show a s ong endency o beha e as pai s. SDF imaging o he pu e NC
54
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
po ion o he TYS sample could no e eal clea ly isible s ipes, which, howe e ,
appea s o be a p oblem o imaging esolu ion as he expec ed APB spacings o Nc a ound
5.5 come close o ou esolu ion limi o app ox. 0.8 nm. We in e p e he beha io o
APBs close o he phase bounda y o be a consequence o a composi ional g adien in he
Fe/S a io as possibly indica ed by SEM-BSE imaging. Because Fe de iciency o he APB
modula ed NC s uc u e can be accomplished by ei he inc easing he spacings o non-
conse a i e APBs o changing hei o ien a ion owa ds he (001) planes (o a
combina ion o bo h), he obse ed beha io is compa ible wi h ou APB modula ion
model and he in e ed p esence o s anded di usion p o iles a ising om exsolu ion o
oili e om he hos py ho i e. As expec ed, SAED pa e ns ob ained om he NC/ oili e
in e ace e eal di use NC sa elli e e lec ion, bu he co esponding Nc alues o he
e lec ions all in he ange o app ox. 5.7 o 6.1. Such high alues a e usually indica i e
o high Fe/S a ios and high densi ies o APBs, con a y o wha we obse e in he
in e ace egions. Howe e , he ela ions be ween Nc, composi ion and APB densi y a e
s ic ly applicable only when he APBs a e dis ibu ed e enly o in he mos ideal case
uni o mly, ha is when he a e age spacing on any in e al is as close as possible o a
ce ain alue (Amelinckx and an Dyck, 1993), which is in ou case he in e se o q’.
Wi hin he obse ed s uc u al g adien his condi ion is no ul illed as dis ances be ween
APBs g adually change. Mo e impo an ly, he clea endency o APBs o occu in pai s
wi h ela i ely la ge spacings in-be ween hem is expec ed o inc ease he appa en
pe iodici y and Nc alue o he s uc u e, because epea dis ances become longe
compa ed o mo e equally spaced a angemen s.
2.4.4. High Resolu ion Imaging (HR-TEM)
As men ioned, HR imaging aces di icul ies when NC-py ho i e is subjec ed o high
elec on cu en densi ies. The HR image o he NC po ion o EUL shown in Figu e 2-9
was ob ained on a p e iously non-i adia ed a ea by adjus ing he beam a he oil edge
ollowed by quick mo emen o he specimen and immedia e exposu e (5 seconds). I s
accompanying FFT pa e n ep oduces well he unal e ed NC SAED pa e n ob ained om
a much la ge a ea a he imaged si e (Fig. 2-9b,c). In his pa icula case we a e con iden
ha he ob ained phase con as in he HR image indeed ep esen s he o iginal s a e o he
specimen. Based on image simula ion (JEMS, S adelmann 2008) o a cons uc ed 5C-
py ho i e s uc u e wi h plana DSDS s acking (see below) he b igh ows can be
55
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
iden i ied as acancy bea ing Fe laye s (no e ha e en unde ideal condi ions he ou
possible V laye ypes canno be dis inguished unambiguously due o p ojec ion issues).
FIGURE 2-9. (a) HR-TEM image o NC-py ho i e in EUL. Al e na ing laye ypes s acked
along he c di ec ion a e clea ly isible and close inspec ion shows ha some laye s la e ally
change con as , indica ing undula ion o APBs. (b) Cen al ow o he FFT pa e n de i ed om
he HR image in a. Fo FFT sampling he images was o a ed 45° o a oid s eak a i ac s
o e lapping he equency maxima. (c) Cen al ow o he NC SAED pa e n ob ained a he
imaged si e. The FFT and SAED pa e n ma ch e y well, indica ing ha he imaged s uc u e in
(a) indeed ep esen s he s uc u al s a e o NC-py ho i es.
Close inspec ion o he image shows ha some acancy laye s ex end o e he wid h
o he image while o he s g adually change hei con as s. This beha io is in e p e ed o
be he esul o wa iness o APBs which is obse ed in SDF images o EUL (Fig 2-7a).
This wa iness can be explained as local jumps o APBs be ween adjacen (001) la ice
planes o he base s uc u e. This ul ima ely leads o ansi ions be ween acan and illed
laye ypes wi hin he same laye plane. Because he HR image in eg a es o e a ela i ely
la ge specimen hickness o app oxima ely 20 nm (compa e o he wid h o Fig. 2-9a being
30 nm), he i egula jumps will esul in g adual con as changes. Also he ypical scale
o wa iness o ens o nm as seen in Fig. 2-7a is well consis en wi h wha is seen in he
HR image.
56
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
2.5. Discussion
2.5.1 A T ansla ion In e ace Modula ion Model o NC-Py ho i es
Based on ou TEM obse a ions we ind ha he e is compelling e idence ha he
s uc u al di e si y obse ed in SAED pa e ns and SDF images o non-in eg al NC-
py ho i es can be explained in e ms o a TIM s uc u e model. The ansla ion in e aces
a e APBs o med by o de ing o Fe acancies in he Fe subla ice o he NiAs- ype base
s uc u e. The esul ing NC s uc u es can be seen as supe posi ion o wo modula ions:
Fi s , an occupa ion modula ion o he NiAs- ype base s uc u e o ming he 4C
supe s uc u e by a ela i ely simple acancy o de ing scheme. Second, a ansla ion
in e ace modula ion by egula a angemen o APBs ela ed o he p ima y 4C s uc u e.
This model bea s esemblance o p e iously sugges ed ‘ou -o -s ep’ and an i-phase de ec
models (Pie ce and Buseck 1974) bu is mo e p ecise on he ac ual na u e o he in ol ed
ansla ion in e aces and lexible enough o explain he a iabili y o NC-py ho i e
s uc u es and composi ions. On he o he hand, he supe space app oach o Izaola e al.
(2007) is a single s ep occupancy modula ion, bu in p inciple ully compa ible wi h ou
TIM model, which we see as a iable ex ension owa ds unde s anding he eal s uc u e
o modula ed py ho i es.
In o de o explain why a wo s ep modula ion model p o ides a be e desc ip ion he
eal s uc u e, we will discuss he idealized laye s acking. In essence, he supe space
model o Izaola e al. (2007) p oduces disc e ely modula ed supe s uc u es by inse ing
addi ional F laye s in o he basic 4C laye sequence, p oducing ei he pe iodic o ape iodic
(bu uni o m) s acking sequences pa allel o (001). Because he so p oduced double F
laye s ca y an Fe excess, he esul ing phases will ha e highe Fe/S a ios han 4C-
py ho i e and ollow s ic ly he ela ion 2x = 1/Nc as spacings be ween double laye s a e
e enly dis ibu ed (he e 1/Nc co esponds o he modula ion pa ame e γ o Izaola e al.,
2007). A simple model o how mo e complica ed s uc u es can be g adually de i ed by
inse ion o ex a F laye s is shown in Figu e 2-10a. S a ing om he 4C s uc u e he
addi ion o one ex a F laye esul s in a 4.5C s uc u e in which one double F laye (“D”
as opposed o single F laye s designa ed “S”) exis s. Basically only one unique inse ion
op ion exis s as he ac ual sequence o acan laye s V is solely dependen on how he
o igin is chosen (as ou lined abo e) and hence he e a e ou ully equi alen ealiza ions
(DSSS, SDSS, SSDS, SSSD). Adding ano he F laye o o m a 5C s uc u e now aces
h ee op ions as he e a e h ee dis inc si es o inse ion in o he DSSS s uc u e: he D
57
CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
he TYS sample, he e y sha p composi ional g adien s a he 4C/NC in e aces in ou
EUL and NYS samples poin o well equilib a ed assemblages (basically he Fe/S g adien
is con ined o he size o he obse ed node s uc u es, i.e., <20 nm). The e o e, he
associa ion o Nc ≈ 4.85 py ho i e wi h exsol ed 4C-py ho i e in wo o ou samples, as
well as he coexis ence o Nc = 4.88 py ho i e and 4C-py ho i e obse ed by Mo imo o
e al. (1975b), poin s o a a o ed s abili y o NC-py ho i es wi hin he ange o Nc = 4.8
o 4.9 – a leas wi h ega ds o ypical empe a u es o he uppe mos c us , whe e he
samples esided o geological imescales. Fo py ho i es ha ing Nc > 5 he si ua ion
appea s somewha mo e complica ed as he ange o ealized Nc alues seems o be much
b oade as shown by ou TYS sample and he X- ay esul s o Mo imo o e al. (1975b),
who ound a wide ange o Nc alues as well as coexis ing oili e wi hin a single sample.
These indings may sugges ha he associa ion o Nc ≈ 5.5 py ho i e and exsol ed oili e
is ano he phase assemblage s able a low empe a u es o <150°C, whe e oili e becomes
s able. Clea ly, mo e obse a ions on na u ally occu ing exsolu ion assemblages a e
equi ed in o de o de i e eliable phase ela ions.
Ob iously, APBs o m by o de ing o acancies upon he ansi ion om one o he
high empe a u e s uc u al a ian s o py ho i e (e.g., he diso de ed 1C-py ho i e o he
poo ly cha ac e ized, maybe pa ially diso de ed NA-py ho i e). Howe e , a p esen i
emains unknown wha d i ing o ces a e esponsible o s uc u al o ganiza ion in
in e ace modula ed py ho i es and wha ene ge ic con ibu ions s abilize hem wi h
espec o he mo e simple s uc u ed end-membe s 4C-py ho i e and oili e. Gene ally,
modula ed s uc u es a ise om he compe i ion o in e ac ions imposing di e en
s uc u al pe iods when conside ed on hei own (Amelinckx e al., 1989). Fo example, in
case o a cha ge densi y wa e modula ed s uc u es a oms a e sligh ly shi ed ou o hei
ideal posi ions due o he exis ence o a modula ion in elec on densi y ha ing a pe iod
di e en om he epea o he c ys al s uc u e. The accompanying inc ease o elas ic
ene gy is o e compensa ed by a dec ease o elec onic ene gy due o modi ica ions o he
Fe mi su ace and hus allows o he o ma ion o a s able displacemen modula ion. On
he o he hand, in cases o occupancy o in e ace modula ed s uc u es o he phenomena
like compe ing nea es and nex nea es neighbo elec os a ic o magne ic in e ac ions
may play signi ican oles and appea especially in case o py ho i e wo h conside ing
due o he inc eased mobili y o Fe in he p esence o acancies (Condi e al., 1974). The
unde s anding o mechanisms and d i ing o ces behind s uc u al o ganiza ion in
64

CHAPTER 2 TRANSLATION INTERFACE MODULATION IN PYRRHOTITE
65
modula ed py ho i es p omises in e es ing and signi ican implica ions o many ields o
mine al and ma e ials sciences due o he ubiqui ous occu ence o his mine al and i s
highly a iable magne ic and physicochemical p ope ies.
2.6. Acknowledgemen s
This is publica ion no. GEOTECH-1526 o he R&D p og am GEOTECHNOLOGIEN
unded by he Ge man Minis y o Educa ion and Resea ch (BMBF) and Ge man
Resea ch Founda ion (DFG), g an 03G0718A. We also acknowledge inancial suppo
p o ided by he DFG Leibniz p og am (LA 830/14-1 o FL). The au ho s a e g a e ul o R.
Ca acas o he discussion o modula ed s uc u es and N. Miyajima o assis ance wi h
TEM wo k. Re iews by A. P ing and an anonymous e iewe helped o imp o e he
manusc ip and a e g a e ully acknowledged.
CHAPTER 3 PYRRHOTITES IN CHONDRITES
CHAPTER 3 The Nanoscale Mine alogy o Fe,Ni Sul ides in P is ine and
Me amo phosed CM- and CM/CI-like Chond i es: A emp ing o Tap a
Pe ogene ic Reco d
by Dennis Ha ies1,2* and Falko Langenho s 2
1Baye isches Geoins i u , Uni e si y o Bay eu h, D-95440 Bay eu h,
Ge many. 2Ins i u ü Geowissenscha en, F ied ich-Schille -Uni e si ä
Jena, Ca l-Zeiss-P omendae 10, D-07745 Jena, Ge many.
*Co esponding au ho . Email: dennis.ha ies@uni-bay eu h.de
3.1. Abs ac
We ha e sampled sul ide g ains om one p is ine CM2 chond i e (Yama o [Y-]
791198), one he mally me amo phosed CM2 chond i e (Y-793321), and wo anomalous,
me amo phosed CM/CI-like chond i es (Y-86720 and Belgica [B-] 7904) by he ocused
ion beam (FIB) echnique and s udied hem by analy ical ansmission elec on
mic oscopy (TEM). Ou s udy aims a explo ing he po en ial o sul ide assemblages and
mic os uc u es o deciphe p ocesses and condi ions o chond i e pe ogenesis. Complex
NC-py ho i e- oili e-pen landi e exsolu ion ex u es occu in g ains o Y-791198 and Y-
793321 and, polyc ys alline 4C-py ho i e-pen landi e-magne i e agg ega es occu in Y-
791198, poin ing o di e se condi ions o gas-solid in e ac ions in he sola nebula.
Coa se exsolu ion ex u es o Y-793321 g ains indica e highe long e m a e age
empe a u es in he < 100 °C ange compa ed o Y-791198 and o he CM chond i es.
Sul ide mine alogy o Y-86720 and B-7904 is domina ed by agg ega es o pu e oili e and
me al, indica ing me amo phic equilib a ion a S2 o he i on- oili e bu e . Absence o
magne i e in equilib ium wi h sul ide and me al in Y-86720 indica es highe peak
empe a u es compa ed o B-7904, in which coexis ence o oili e, me al, and magne i e
cons ains me amo phic empe a u e o less han 570 °C. NC-py ho i e occu s in bo h
me eo i es as nm-wide ims on oili e g ains and, oge he wi h equen anhyd i e,
indica es a e og ade me amo phic s age a highe S2 sligh ly abo e he FMQ-Po bu e .
Fine-g ained oili e-oli ine in e g ow hs in bo h me eo i es sugges he p e-me amo phic
p esence o ochilini e-se pen ine in e laye phases, poin ing o mine alogical CM a ini y.
Pseudomo phs a e euhed al py ho i e c ys als in Y-86720 in u n sugges CI a ini y as
do p e iously published O iso opic da a o bo h me eo i es.
66
CHAPTER 3 PYRRHOTITES IN CHONDRITES
3.2. In oduc ion
3.2.1. CM and CM/CI-like Chond i es
CM chond i es a e one o he cosmochemically mos p imi i e me eo i e g oups, bu a
he same ime, hey a e p obably one o he mine alogically mos complex ock ypes.
Mos cha ac e is ically, hey a e ich in ine-g ained ma ix ma e ial and expe ienced
ex ensi e aqueous al e a ion (McSween 1979; Zolensky e al. 1997), documen ed by he
p esences o phyllosilica es ( ypically Fe- ich se pen ines; Bunch and Chang 1980;
B owning e al. 1996), ochilini e (a complex Fe- ich hyd oxide/sul ide in e laye mine al;
Zolensky 1987), and Ca and Ca-Mg ca bona es (Johnson and P inz 1993; Benedix e al.
2003). The low empe a u e mine al assemblage ( ypically o med a empe a u es
signi ican ly less han 100 °C; Guo and Eile 2007; Zolensky e al. 1993) indica es an
episode o exposu e o p ima y, anhyd ous mine als o a wa e - ich en i onmen . While
mos al e a ion p obably occu ed on he CM pa en body, he e is ample e idence ha
some componen s migh ha e been hyd a ed in he sola nebula (Me zle e al. 1992;
Bischo 1998; Ciesla e al. 2003). A simila issue is he o igin o py ho i e and
pen landi e p esen in CM chond i es (Bunch and Chang 1980). Pen landi e and py ho i e
ha e equen ly, and o en implici ly, been assumed o be p oduc s o pa en -body
al e a ion o oili e o me al (e.g., Hanowski and B ea ley 2001), while py ho i e i sel
(Fe de icien Fe1-xS) has o en been o e looked due o i s simila i y o oili e
(s oichiome ic FeS). Py ho i e is an ex emely a iable mine al and, depending on
o ma ion condi ions, can occu in se e al composi ionally and c ys allog aphically
dis inc o ms (e.g., Wang and Sal eson 2005; Ha ies e al. 2011). Zolensky and Thomas
(1995) showed ha py ho i e is abundan in in e plane a y dus pa icles (IDPs) and
sugges ed i s o ma ion ia ex ended sul ida ion o oili e in he sola nebula. Simila ly,
Boc o e al. (2002) and B ea ley and Ma inez (2010) sugges ed ha py ho i e- and
pen landi e-bea ing g ains in CM chond i es a e p ima y p oduc s o he nebula − ye ,
he e has been li le explo a ion o hese mine als in chond i es.
Some CM and CM/CI-like chond i es expe ienced he mal me amo phism ha pa ially
led o he dehyd a ion o phyllosilica es. Pa icula ly among he me eo i es collec ed in
An a c ica by Japanese NIPR ield pa ies (Yama o and Belgica eco e y si es) a la ge
ac ion o CM- and CI-like chond i es displays he mo-me amo phic o e p in s, which
ha e spa ked ex ensi e s udies o hese ocks (e.g., Akai 1988; Ikeda 1992 and e .
he ein). The numbe o CM and CM/CI-like chond i es known o ha e been he mally
67
CHAPTER 3 PYRRHOTITES IN CHONDRITES
a ec ed is s eadily g owing (e.g., Naka o e al. 2011), indica ing ha me amo phism and
dehyd a ion migh be a ela i ely common p ocess in he e olu ion o hyd ous as e oids.
Due o he complex phase ela ionships and he mochemis ies o Fe and Fe,Ni sul ides,
hei pe ogene ic eco d wi hin hese me eo i es is in e es ing and in he p ocess o being
apped (e.g., Kimu a e al. 2011).Howe e , he s udy o sul ides emains challenging o a
leas wo easons: Fi s , he small sizes and small-scale in e g ow hs o di e en sul ide
phases. Second, he ela i ely uncons ained na u e and his o y o sul ides in he p e-
me amo phic chond i es.
In his con ibu ion we ocus on he sul ide mine alogies o An a c ic CM and CM/CI-
like chond i es ha expe ienced e y di e en deg ees o he mal me amo phism, om
none o se e e. We o e come he challenge o small size by using ocused ion beam (FIB)
p epa a ion and analy ical ansmission elec on mic oscopy (TEM). The aim is o
deciphe he phase assemblages and mic os uc u es o Fe sul ides, in pa icula hose o
py ho i es, in o de o ob ain cons ain s on key pa ame e s o p ima y o ma ion and
seconda y al e a ion and me amo phisms, including sul u and oxygen ugaci ies,
me amo phic empe a u es, and cooling a es.
3.2.2. P e ious Wo k and Cons ain s on Me amo phic His o ies
P ominen membe s o he anomalous g oup o me amo phosed CM/CI-like me eo i es
a e Y-82162, Y-86720, and B-7904 (o en e e ed o as Belgica g ouple ). Besides
mine alogical e idence o anomalous he mal his o ies, hese ocks also display
pe og aphic, mine alogical, geochemical, and iso opic cha ac e is ics ha place hem in
unce ain ela ionship wi h bo h CM and CI chond i e g oups (Bischo and Me zle 1991;
Ikeda 1992). Oxygen iso opic composi ions o Y-82162, Y-86720, and B-7904 discussed
by Clay on and Mayeda (1999) a e e y simila bu dis inc om ypical CM and CI
chond i es, al hough a gene ic link o he CI g oup may be possible h ough mass-
dependen oxygen iso ope ac iona ion du ing dehyd a ion. Y-793321 is an a ypical CM2
chond i e ha has expe ienced me amo phic hea ing, leading o he b eakdown o
ochilini e and pa ial dehyd a ion o phyllosilica es (Nakamu a 2006). On he con a y o
he Belgica g ouple , Y-793321 shows O iso opic a ios much close o he CM end and
could ha e o igina ed om a a he weakly hyd a ed CM p ecu so (Clay on and Mayeda
1999). T ace elemen geochemis y (Paul and Lipschu z 1990; Yamamo o and Nakamu a
1990) places Y-86720 in p oximi y o he CM g oup o be ween CM and CI, and B-7904
68
CHAPTER 3 PYRRHOTITES IN CHONDRITES
also in p oximi y o he CM g oup. The ace elemen composi ion o Y-793321 is epo ed
o be well consis en wi h ypical CM2 chond i es (Tonui e al. 2002). The Belgica
g ouple chond i es ha e expe ienced me amo phic hea ing in he ange o abou 500 o
800 °C. Y-793321 was hea ed o a much lesse deg ee. A compila ion o es ima ed
me amo phic empe a u es is gi en in Table 3-1. A la ge unce ain y ac o in hese
es ima es a ises om he unknown du a ion o hea ing, because many c i e ia ely on
s ongly kine ically con olled p ocesses, such as phyllosilica e dehyd a ion and mig a ion
o mobile ace elemen s. Naka o e al. (2008), o example, es ima ed he hea ing ime o
B-7904 in he o de o 10 o 1000 days a 700 °C and 1 o 100 hou s a 890 °C. O ganic
geochemis y s udies by Shimoyama e al. (1991), Ki ajima e al. (2002), and Na aoka e
al. (2004) mos ly ag ee wi h he epo ed ela i e deg ees o me amo phic hea ing, bu also
indica e some inconsis encies.
TABLE 3-1. Compila ion o epo ed me amo phic empe a u es o Y-793321 and he Belgica
g ouple chond i es.
Me eo i e S age* Tempe a u e ange (°C) Sou ce
Y-793321 II, B 300-500 2
Y-793321 II, B <500 7, 8
Y-793321 II, B <500 9, 10
Y-82162 III/II 600-800 2, 5
Y-82162 III/II 600-700, <Y-86720 3
Y-82162 III/II <400 6
Y-82162 III/II <700, <Y-86720 7, 8
Y-86720 IV, C 700-850 2, 5
Y-86720 IV, C 600-700, >Y-82162 3
Y-86720 IV, C 500-700 6
Y-86720 IV, C >500 1
Y-86720 IV, C ≤700 7, 8
B-7904 IV, C 750-900 2, 5
B-7904 IV, C 600-700, <Y-82162 3
B-7904 IV, C <600, 400-500 4
B-7904 IV, C
>500, ≈Y-82162 7, 8
B-7904 IV, C 700-890 11
*Hea ing s age (nume als I o IV) o Nakamu a (2005), me amo phic ca ego y (le e s A o C) o
Kimu a e al. (2011). 1: Tomeoka e al. (1989b), 2: Akai (1990), 3: Paul and Lipschu z (1990), 4:
Zolensky e al. (1991), 5: Akai (1992), 6: Zolensky e al. (1993), 7: Lipschu z e al. (1999), 8:
Tonui e al. (2002), 9: Nakamu a (2005), 10: Nakamu a (2006), 11: Naka o e al. (2008).
We ha e included Y-791198 in o ou s udy, because his me eo i e is ega ded as one o
he mos p imi i e CM chond i es known. Tex u al and chemical e idence indica es ha
69

CHAPTER 3 PYRRHOTITES IN CHONDRITES
his me eo i e is a p ima y acc e iona y ock ha expe ienced li le o in e media e deg ees
o pa en body aqueous al e a ion (Me zle e al. 1992; Rubin e al. 2007), no he mal
me amo phism (Shimoyama e al. 1991; Ki ajima e al. 2002; Na aoka e al. 2004), and no
impac -induced b eccia ion (Me zle e al. 1992).
3.2.3. Py ho i es in he Fe(+Ni)-S Sys em
Despi e i s simple composi ion, py ho i e is a ema kably complex mine al, demanding
he e a sho o e iew o i s mine alogy. Py ho i e, being Fe1-xS wi h x ypically be ween
0 and 0.125, is a non-s oichiome ic i on sul ide wi h Fe-si e acancies. Rele an
py ho i e composi ions occupy he Fe-S sys em be ween 46 and 50 a % Fe and o m a
se ies be ween Fe0.875S and s oichiome ic FeS ( oili e). The (omission) solid solu ion is
mos ly comple e a empe a u es abo e 320 °C and he Fe acancies a e andomly
dis ibu ed in he hexagonal, NiAs based la ice (1C-py ho i e; G øn old and S ølen 1992;
Wang and Sal eson 2005). I has been shown by se e al s udies ha he Fe/S a io and he
co esponding x alue o solid 1C-py ho i e a T > 500 °C is p ima ily a unc ion o
empe a u e and sul u ugaci y ( S2 ; e.g., Rau 1976; Toulmin and Ba on 1964) as shown
in Figu e 3-1a. A gi en T > 320 °C, a speci ic py ho i e composi ion is in equilib ium
wi h gaseous S2 o de e mined ugaci y. The py ho i e ield is bounded by he eac ions:
FeS(s) → Fe(s) + 0.5S2(g) (3-1)
Fe1-xS(s) + (0.5-x)S2(g) → (1-x)FeS2(s) (3-2)
Reac ion 3-1 desc ibes he i on- oili e bu e (IT; e.g., F oese and Gun e 1976), which
ixes S2 as unc ion o empe a u e. Reac ion 3-2 is he py i e-py ho i e bu e . The
addi ion o Ni in o he hexagonal monosul ide solid solu ion (MSS, Fe1-xS – Ni1-xS) a 600
°C inc eases he me al/sul u (M/S) a io a gi en S2 and dec eases he me al de iciency x
(Kosyako e al. 2003; Ragha an 2004). Fo example, he equilib ium log S2 o app ox.
x = 0.08 inc eases om −5 o Fe0.92S o −4 o (Fe0.55Ni0.37)S. In he p esence o sui able
edox couples, S2 is cons ained by oxygen ugaci y O2 and ice e sa, e.g., h ough he
eac ion wi h magne i e (Whi ney 1984):
70
CHAPTER 3 PYRRHOTITES IN CHONDRITES
3Fe1-xS(s) + (2-2x)O2(g) → (1-x)Fe3O4(s) + 1.5S2(g) (3-3)
These ela ionships allow o mula ing S2- O2 bu e s as o example he FMQ-Po bu e
o Eggle and Lo and (1993) shown in Figu e 3-1b.
FIGURE 3-1. S2-T plo s o he Fe-S sys em and a ious bu e assemblages a 1 ba o al p es-
su e. (a) Bounding eac ions and Fe-de iciency isople hs o diso de ed 1C-py ho i e exp esses as
x in Fe1−xS. Isople hs a e based on Rau (1976), he i on- oili e (T o+Fe) bu e is also shown
based on Toulmin and Ba on (1964) (do ed line). The sul u condensa ion cu e is based on
JANAF da a (Chase e al. 1985), he py i e-py ho i e (Py+Po) bu e on Lusk and B ay (2002),
and he mel ing cu e on Rau (1976). (b) Mine al eac ion isople hs o he ayali e-magne i e-
qua z-py ho i e (Fa+Mag+Qz+Po) bu e o Eggle and Lo and (1993) and he wüs i e-
magne i e-py ho i e (Wus+Mag+Po) bu e (based on F os 1991 and Whi ney 1984). Also
shown a e isople hs o he anhyd i e-magne i e-py ho i e assemblage a di e en ac i i ies o
CaO (Anh-Mag-Po-CaO). The isople hs a e de ined by he in e sec ion o common O2 isoba s
(labeled in log uni s) o he anhyd i e dissocia ion (Anh, Eq. 6, da a om Ba in e al. 1989 and
JANAF/Chase e al. 1985) and he magne i e-py ho i e eac ion (Mag+Po, Eq. 3; Whi ney 1984).
This is shown o uni y ac i i y o CaO.
The o ma ion o py ho i e in he sola nebula was a ibu ed by Ke idge (1976) and
Zolensky and Thomas (1995) o ex ended sul ida ion o p e iously o med oili e by H2S.
In a simple sys em, his can be exp essed by he eac ions:
Fe(s) + H2S(g) → FeS(s) + H2(g) (3-4a)
(1-x)FeS(s) + xH2S(g) → Fe1-xS(s) + xH2(g) (3-4b)
71
CHAPTER 3 PYRRHOTITES IN CHONDRITES
The eac ions a e mo e complex in
na u e, because he ini ial me al
con ains Ni and o he componen s,
leading o po en ially complex eac ion
pa hs (Lau e a e al. 1997). As ou lined
abo e and shown in Figu e 3-1a, he
composi ional a iable x o non-
s oichiome ic py ho i e depends on T
and S2, he la e being de e mined by
T, P, and he H2S/H2 a io. No ably, he
p essu e-dependence o he Fe1-xS+S2
equilib ium is a he small (Toulmin
and Ba on 1964). This sugges s ha
py ho i e o ma ion in exchange wi h a
gas phase can, in p inciple, be
a ibu ed o S2 a alues highe han
he IT-bu e . Hence, py ho i e will no
o m a condi ions when oili e, Fe,Ni
me al, and ambien gas a e in
equilib ium.
A empe a u es below 320 °C, he
Fe-S sys em wi hin he py ho i e
composi ional ange con ains se e al
one- and wo-phase ields, which a ise
om (pa ial) o de ing o Fe acancies
and o ma ion o complex supe s uc u es (Fig. 3-2). A ambien empe a u es, NC-
py ho i es exis , in which he c dimension o he supe s uc u e is N imes ha o he
undamen al NiAs- ype cell. N anges mos ly be ween 4 and 6 and can ake in eg al (4C,
5C, 6C) as well as non-in eg al alues. The mos common and bes es ablished py ho i e
s uc u e a ambien condi ions is monoclinic 4C-py ho i e (Fe0.875S o Fe7S8), in which
he acancy o de ing quad uples he NiAs based c la ice dimension (Be au 1953; Powell
e al. 2004). In e es ial samples, 4C-py ho i e is ypically associa ed wi h NC-
py ho i es, in which N akes non-in eg al alues be ween 4 and 5, due o ape iodic
FIGURE 3-2. Simpli ied, low empe a u e phase
diag am o he Fe-S sys em based on Nakazawa
and Mo imo o (1970) and Kissin and Sco (1982).
Many o he phase bounda ies a e en a i e and
shown dashed. 2C, 4C, 5C, 11C, 6C designa e py -
ho i e supe s uc u es wi h hei c-dimension mul-
iplici y o he undamen al NiAs- ype cell. 2C is
oili e, 4C is monoclinic py ho i e (Fe7S8 o
Fe0.875S). 5C, 11C, and 6C a e ‘hexagonal’ py -
ho i es (Fe9S10, Fe10S11, and Fe11S12, espec i ely).
NC designa es py ho i es wi h a iable and o en
non-in eg al c dimension supe s uc u e mul iplic-
i y, N alues a e gi en as do ed lines (Nakazawa
and Mo imo o 1970). 4.85C is a NC-py ho i e
wi h non-in eg al mul iplici y ha commonly coex-
is s wi h 4C-py ho i e a oom empe a u e (Ha -
ies e al. 2011). MC- and NA-py ho i es a e high
empe a u e supe s uc u es. 1C-py ho i e has
comple ely diso de ed acancies and a NiAs- ype
uni cell.
72
CHAPTER 3 PYRRHOTITES IN CHONDRITES
s uc u al modula ions, and is posi i ely co ela ed wi h he Fe/S a io (Ha ies e al. 2011;
Mo imo o e al. 1975b). A Fe/S close o uni y, 1C-py ho i e can pe sis down o
empe a u es o app oxima ely 100 °C be o e acancies o de in o supe s uc u es. In his
composi ional ange, oili e is a commonly obse ed exsolu ion phase coexis ing wi h
NC-py ho i es, which o med om he diso de ed 1C phase. Expe imen al s udies by
No iko e al. (1977) showed ha du ing cooling and exsolu ion o oili e he s uc u al
e olu ion o coexis ing py ho i e is a he complica ed and p oceeds in a leas wo s ages.
NC-py ho i e coexis ing wi h oili e a oom empe a u e shows ei he non-in eg al N
alues o a ound 5.5 (~Fe0.91S o Fe10S11; Ha ies e al. 2011; Mo imo o e al. 1975b) o an
in eg al alue o 6 (Fe0.92S o Fe11S12; Becke e al. 2010a; Mo imo o e al. 1975a;
Nakazawa and Mo imo o 1970).The o igin o his dicho omy is no well known.
Expe imen al esul s by Nakazawa and Mo imo o (1970) shown in Figu e 3-2 sugges ha
du ing cooling o NC-py ho i e he N alue inc eases con inuously, and some o he non-
in eg al NC-py ho i es migh be me as able due o sluggish o de ing kine ics. Hence,
some o he obse ed assemblages migh no ep esen equilib ium s a es a oom
empe a u e bu a he ozen-in s ages o hei cooling his o y. The in luence o Ni
con en s on he phase ela ionships o py ho i e below 320 °C is no well known, bu
gene ally Ni concen a ions a e low ( ypically less han 0.3 a %; Vaughan and C aig 1978;
E schmann e al. 2004) due o exsolu ion o pen landi e, (Fe,Ni)9S8. The la e is he
ypical ca ie o Ni in exsol ed e es ial MSS. The onse o pen landi e exsolu ion
depends on he M/S a io and Ni con en o he MSS and commences be ween 610 and
300 °C (Nald e e al. 1967; Kelly and Vaughan 1983; E schmann e al. 2004).
3.3. Sample P epa a ion and Analy ical Me hods
3.3.1. Sample P epa a ion
We ha e selec ed esh in e io agmen s o Yama o-791198 (,97), Yama o-793321
(,101), Belgica-7904 (,114), and Yama o-86720 (,86).in o de o a oid wea he ing e ec s
and he mal o e p in om a mosphe ic passage. F agmen s we e epoxy moun ed and
ca e ully polished. Ca e was aken no o hea he samples abo e oom empe a u e in
o de o a oid any po en ial de e io a ion o he o iginal sul ide mic os uc u es.
3.3.2. Analy ical Me hods
Fo mic op obe analysis, a JEOL JXA-8200 equipped wi h i e wa eleng h dispe si e
73
CHAPTER 3 PYRRHOTITES IN CHONDRITES
3-5d,e). The euhed al sul ide g ains a e gene ally no associa ed wi h he Ca haloes
desc ibed abo e. We did no obse e pen landi e, nei he as exsol ed phase no as sepa a e
g ains. The mo phologically dis inc sul ide g ains show no signi ican di e ence in
composi ion and ha e M/S a ios indisce nible om uni y (0.998±0.007 o la ge g ains,
0.995±0.006 o small, i egula g ains) and e y low Ni con en s (<0.2 % m/m; Tab. 3-2),
consis en wi h oili e. Simila ly o B-7904, he ine-g ained sul ides a e o en in ima ely
in e g own wi h minu e Mg silica e g ains (Fig. 3-5e, ). Many o he sul ide g ains,
including he euhed al ones, a e associa ed wi h Fe,Ni me al g ains (Fig. 3-5d), which
show la ge a ia ions in Ni concen a ions (Tab. 3-2), anging om e y Ni-poo kamaci e
o Ni- ich aeni e.
3.4.2. Composi ions in he Fe-Ni-S Te na y
In a e na y Fe-Ni-S diag am (Fig. 3-6a), including he phase ields and ie lines a 200
°C a e C aig (1973), he composi ions o coa se pen landi e in Y-791198 all a he end o
ie lines connec ing o Ni- ich MSS. These MSS composi ions a e no obse ed among he
low-Ni sul ides and almos all analyses clus e closely nea he edge be ween he FeS and
Fe7S8 composi ions. The same applies o he low-Ni sul ide composi ions obse ed in Y-
793321, which show a sligh end owa d pen landi e composi ions owing o mixed
analyses and sligh ly coa se pen landi e blebs in Y-793321. Because he MMS ield is
expec ed o sh ink wi h dec easing empe a u es below 200 °C (C aig 1973), he MMS
will become poo e in Ni, and coexis ing pen landi e will become iche in Ni. This
indica es ha he coexis ing Fe,Ni sul ides obse ed in Y-791198 ha e equilib a ed a
empe a u es well below 200 °C as i is o en obse ed in e es ial samples, whe e e y
Ni-poo py ho i e occu s abundan ly nex o pen landi e (e.g., E schmann e al. 2004).
Un o una ely, i is i ually impossible o ob ain he bulk composi ion o indi idual
sul ide agg ega es om he composi ions o he cons i u ing phases, because he coa se
g ained na u e o seg ega ed pen landi e ende s es ima es o i s olume ac ion highly
unce ain.
80

CHAPTER 3 PYRRHOTITES IN CHONDRITES
FIGURE 3-6. Fe-Ni-S e na y diag ams o sul ide composi ions in he me eo i es s udied.
Phase ield and ie lines a e d awn o 200 °C based on C aig (1973). A his empe a u e wo
ex ended MSS ields (labeled MSS1 and MSS2) s ill exis . (a) Da a o Y-791198 and Y-793321.
(b) Da a o B-7904 and Y-86720. Da a poin s ou side he MSS1 ield and abo e he pen landi e
line cen e ed a Fe5Ni4S8 indica e mixed measu emen s. The absence o da a poin s o Y-791198
and Y-793321 in he Ni- ich pa o he MSS1 ield indica es equilib a ion below 200 °C.
The alleged pen landi e g ains measu ed in B-7904 (Fig. 3-6b) plo in he Fe-Ni-S
e na y be ween Fe- ich pen landi e and he oili e composi ion, whe e all he Ni-poo Fe
sul ides o B-7904 and Y-86720 clus e . Likely, hese in e media e pen landi e-like
composi ions ep esen small scale mix u es o oili e and Fe- ich pen landi e. The
pen landi e mixing line in B-7904 none heless appea s o poin o a Fe- ich pen landi e
composi ion, wi h Fe/Ni o app oxima ely 1.9 o 2.0. Acco ding o Kaneda e al. (1986)
such Fe- ich pen landi e composi ions migh poin o low S2 du ing equilib a ion wi h
coexis ing MSS.
3.4.3. TEM obse a ions
3.4.3.1. Yama o-791198
We ha e p epa ed FIB oils o wo pen landi e-bea ing M- ype g ains (98F01, 98F02;
81
CHAPTER 3 PYRRHOTITES IN CHONDRITES
Fig. 3-4b) and one P- ype agg ega es o mic oc ys als (98F06; Fig. 3-4d). The in e nal
s uc u e o compac M- ype g ains consis s o nanoscale, lame-like, and
c ys allog aphically cohe en in e g ow hs o oili e and winned NC- ype py ho i e,
associa ed wi h sub-µm sized, od-shaped pen landi e g ains (Fig. 3-7a,b,c; Fig. 3-8a).
Sample 98F02 shows a hick im o pu e pen landi e enclosing he NC-py ho i e- oili e-
pen landi e in e g ow hs (Fig. 3-7a).
FIGURE 3-7. BF-TEM images o sul ides in Y-791198 and Y-793321. FGR = ine-g ained im.
The dashed lines indica e he aces o he (001) la ice planes o oili e and py ho i e. (a) Y-
791198 (98F01) showing a con inuous im o pen landi e a ound an inne pa consis ing o oili e
+ NC-py ho i e in e g ow hs and pen landi e blebs. (b) De ail o lame-like oili e + NC-
py ho i e in e g ow hs in Y-791198 (98F02), no pen landi e im is p esen a he g ain ma gin,
adjacen o he ma ix. (c) De ail o in e nally exsol ed pen landi e blebs in Y-791198 (98F01). (d)
T oili e + 6C-py ho i e in e gow hs in Y-793321 (21F05). (e) T oili e + 6C-py ho i e
in e g ow hs and pen landi e in Y-793321 (21F01). The sul ide ex u es in Y-793321 (d+e) a e
subs an ially coa se han in Y-791198 (a-c). ( ) Scaly, highly po ous ma e ial eplacing he sul ide
in Y-793321 (21F01). SAED (Fig. 3-10) shows he eplacemen o be a mix u e o nanoc ys alline
Fe sul ide and magne i e, likely being he mal b eakdown p oduc s o ochilini e.
Flame-like oili e-py ho i e lamellae in bo h M- ype g ains a e sub-pa allel o (001)
and ha e ypical wid hs in he ange o 80 o 200 nm. T oili e and py ho i e sha e a
common o ien a ion o hei sul u subla ice and a e well dis inguishable in [210]NiAs
SAED pa e ns due o hei di e en supe s uc u es (Fig. 3-8e). Table 3-3 lis s N alues
de e mined om SAED pa e ns using he leng h a ios o in e se la ice ec o s c* and q
(Ha ies e al. 2011; Fig. 3-8a,e).
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CHAPTER 3 PYRRHOTITES IN CHONDRITES
FIGURE 3-8. TEM-SAED pa e ns o sul ides in Y-791198 and Y-793321. (a) Twinned NC-
py ho i e in Y-791198 (98F02) in combined zone axes (ZA) [100] and [110] (based on NiAs- ype
subcell). The s ong basic e lec ions a e spaced by he in e se la ice ec o c* (~1.72 nm-1) o
he p imi i e NiAs- ype cell. The cen al ow o e lec ion is due o he NC supe s uc u e
esul ing om acancy o de ing. Thei a angemen is de e mined by he in e se ec o q. The
a io c*/q is he supe s uc u e mul iplici y N, he e N = 6.01±0.09. T oili e supe s uc u e
e lec ions a e no isible in his ZA. (b+c) NC-py ho i e in Y-793321 (21F01) in he same
o ien a ion as in (a). Va ia ions in in ensi y indica e di e en con ibu ions o win domains a e
minimal shi ing o he sample (<3 µm). N = 5.99±0.07 and 5.97±0.07. (d) Schema ic
ep esen a ion o he SAED pa e ns in (a-c). La ge ci cle a e basic NiAs- ype e lec ions, small
ci cles a e supe s uc u e e lec ions. Filling o ci cles ep esen s he wo win domains. Indexing
is based on he hklm scheme discussed by Ha ies e al. (2011); he e only m > 1 is used o cla i y.
(e) SAED pa e n o Y-791198 (98F02) showing supe s uc u e e lec ions o winned NC-
py ho i e (cen al ow, ZA [210] and [1-10]) and oili e (adjacen ows, ZA [100]). The
espec i e dis ances c* and q a e ma ked. N = 5.74±0.12. ( ) Twinned 6C-py ho i e and oili e
om Y-793321 (21F01) in same o ien a ion as (e). T oili e e lec ions a e ma ked (in he lowe
pa only). N = 5.94±0.04. (g) Cohe en in e g ow h o py ho i e+ oili e and pen landi e in Y-
791198 (98F01). Po/T o e lec ions a e ma ked wi h dashed ci cles, no mal ype ace, pen landi e
e lec ions wi h solid ci cles, i alic ype ace. T oili e ZA is [210] and only NiAs- ype e lec ions
a e isible, pen landi e ZA is [101] and a leas wo o ien a ion a ian s (F ancis e al. 1976) occu ,
he second is labeled ‘b’. (h) Same in e g ow h in Y-793321 (21F01), ma king o e lec ions is he
same as in g. ZAs a e [100] o oili e and [112] o pen landi e.
In case o g ain 98F01, N alues a e consis en wi h 6C-py ho i e (ideally N = 6), bu
he alues o g ain 98F02 (5.63±0.13 and 5.74±0.12), ob ained om wo di e en zone
axes o he same c ys al, a e ha dly consis en wi h an in eg al NC supe s uc u e and
indica e a supe s uc u e in e media e be ween 5.5C and 6C. Howe e , no spli ing o
e lec ions expec ed o a non-in eg al supe s uc u e (Ha ies e al. 2011) could be
obse ed in 98F02 due o he a he b oad spo s. This is mos likely due o he small
domain size and in ense winning (see below), leading o somewha diso de ed acancy
a angemen s and possible disappea ance o highe o de supe s uc u e e lec ions (being
83
CHAPTER 3 PYRRHOTITES IN CHONDRITES
esponsible o appa en spli ing).
SAED pa e ns show ha he NC-py ho i e is in ima ely winned by 60° o 120°
o a ion abou i s c axis, esul ing in supe posi ion o wo di e en zone axis pa e ns (Fig.
3-8b,c,d; due o he educed symme y o NC-py ho i e by acancy o de ing, he
di ac ion pa e ns o equi alen zone axes o he undamen al hexagonal NiAs- ype
s uc u e a e no equi alen any mo e in e ms o he supe s uc u e e lec ions). The
o ien a ion ela ionship be ween low-Ni Fe sul ides and pen landi e is equi alen o he
one desc ibed by F ancis e al. (1976) wi h espec o he NiAs- ype undamen al s uc u e
o oili e and py ho i e (Fig. 3-8g): ,
NiAsPn (001)||(111) NiAsPn )10(1||1)10(,
NiAsPn )00(1||)211( . The NC-py ho i e- oili e-pen landi e associa ion occu s ega dless
o whe he sul ide g ains a e immed by pen landi e (98F02) o no (98F01) and occu s
also in di ec con ac wi h he hyd ous, ine-g ained im ma e ial (Fig. 3-7b). The obse ed
sul ide assemblage appea s iden ical o he associa ions in CM2 chond i es desc ibed by
B ea ley and Ma inez (2010) and Maldonado and B ea ley (2011). A ached o he ou e
ma gin o he pen landi e- immed g ain 98F02, we ha e ound an 800 nm sized subg ain
o Fe- ich Zn sul ide, which appea s o be in epi ac ic ela ionship wi h he hos g ain.
The mic oc ys alline agg ega e 98F06 consis s o indi idual g ains o abundan
pen landi e, magne i e, and mino low-Ni Fe sul ide (Fig. 3-9a,b,d). The quali y o he
only Fe sul ide g ain in sui able o ien a ion (wi h an accessible zone axis pe pendicula o
he c di ec ion) was no su icien o eco d a e y clean SAED pa e n, bu he p esence o
supe s uc u e e lec ions in a [100]NiAs-equi alen zone axis clea ly excludes oili e and
indica es py ho i e (Fig. 3-9c). The iple s o supe s uc u e e lec ions seen along he 00l
la ice ow be ween undamen al NiAs e lec ions a e e y simila o winned 4C-
py ho i e (Fe7S8) (Pós ai e al. 2000; Be ge e al. 2011) and could indica e a e y Fe
de icien py ho i e. The N alue de e mined as 3.66±0.33 (1σ; la ge unce ain y due o
b oadness o spo s) is consis en wi h 4C-py ho i e. The majo i y o in e s i ial ma e ial
be ween sul ide and magne i e g ains is ich in Ca phospha e, likely me ili e based on
ele a ed Na concen a ions shown by EDX. An isola ed 600 nm sul ide g ain in he
adjacen ma ix (Fig. 3-9e) was ound o ha e a sui able c ys allog aphic o ien a ion and
he ob ained SAED pa e n (Fig. 3-9 ) indica es a ba ely winned NC-py ho i e wi h an N
alue o 5.48±0.13, being well consis en wi h 5.5C-py ho i e. STEM-EDX elemen al
mapping indica es ha o he small sul ide g ains in he ma ix a e in app oxima ely equal
84
CHAPTER 3 PYRRHOTITES IN CHONDRITES
amoun s Ni- ich (likely pen landi e) and Ni-poo (likely py ho i e).
FIGURE 3-9. P- ype sul ide agg ega e in Y-791198 (98F06). (a) BF-TEM image o he lu y
g ain agg ega e. Cen e o he concen ic agg ega e is benea h he lowe le co ne . Indi idual
g ains a e py ho i e, pen landi e, and magne i e, he la e p e e en ially in he cen al pa , which
is sepa a ed om he ou e pa by a phospha e- ich zone. (b) BF-TEM de ail o he ou e laye .
(c) SAED pa e n o he cen al g ain in (b) showing py ho i e supe s uc u e e lec ions (a ows)
consis en wi h winned 4C-py ho i e (N = 3.66±0.33). (d) TEM-EDX X- ay maps o (a),
illus a ing he dis ibu ion o pen landi e, py ho i e, magne i e, and Ca phospha e (wi h mino Ca
sul a e). Ci cles o guidance. (e) Isola ed py ho i e g ain in he ma ix adjacen o he P-g ain. ( )
SAED pa e n o he py ho i e isola ed ma ix g ain in (e) in ZA [210]. Only weak oili e
e lec ions a e isible. The N alue o py ho i e is 5.48±0.13 and consis en wi h 5.5C-py ho i e
(iden ical o ‘11C-py ho i e’).
3.4.3.2. Yama o-793321
FIB lamellae aken om wo M- ype g ains (21F01, 21F05; Fig. 3-4e, ) show cohe en
in e g ow hs o oili e, NC-py ho i e, and pen landi e simila o Y-791198. Howe e ,
compa ed o Y-791198, he in e g ow hs in bo h g ains o Y-793321 a e much coa se , and
lamellae and pen landi e blebs a e much be e de ined (Fig. 3-7d,e), posi i ely a ec ing
he quali y o SAED pa e ns (Fig. 3-8b,c, ,h). N alues de e mined a e in all cases well
consis en wi h 6C-py ho i e (Tab. 3-3). The o ien a ion ela ionship be ween
py ho i e/ oili e and pen landi e is he same as in Y-791198 (Fig. 3-8h). Typical wid hs o
lamellae and pen landi e p ecipi a es a e in he o de o 300 o 500 nm. Also he e,
py ho i e is in ensely winned, bu , con a y o Y791198, shows in ensi y a ia ions o he
win componen s in SAED pa e ns when he sample is mo ed (Fig. 3-8b,c), indica ing a
85

CHAPTER 3 PYRRHOTITES IN CHONDRITES
coa se domain s uc u e (which un o una ely is ex emely di icul o image, because o
he small dis ances be ween supe s uc u e e lec ions). EDX analysis o pen landi e
lamellae indica es no ob ious in e nal zoning.
G ain 21F01 clea ly shows signs o
eplacemen by a ib ous mine al (Fig. 3-4e,
3-7 ). STEM da k ield imaging e eals ha
he ib ous ma e ial consis s o nume ous
nanoc ys alline domains and, hence, is i sel
a eplacemen by newly o med phases (Fig.
3-10a). SAED shows spo y ing pa e ns
wi h d- alues co esponding o a spinel
s uc u ed mine al, mos closely ma ching
magne i e (Fig. 3-10c). Addi ional
e lec ions in he SAED pa e n poin o he
p esence o a Fe sul ide (ei he oili e o
py ho i e, which a e ha dly disce nible in
his case). EDX indica es ha he
c ys alli es a e composed o Fe, O, and S,
plus subo dina e amoun s o Mg and Si. The
S con en a ies s ongly ega dless o he
dis ance o he in e ace wi h he o iginal
sul ide, suppo ing he p esence o a wo
phase mix u e o magne i e and Fe sul ide.
EDX X- ay mapping shows a signi ican
en ichmen o ch omium up o 5-10 w % in
he nanoc ys alline ma e ial close o he
sul ide in e ace (Fig. 3-10b). I is no clea
whe e C esides, bu likely i is
inco po a ed in o he magne i e. The
composi ion and mo phology o his
magne i e-sul ide assemblage s ongly
sugges s i o be a b eakdown p oduc o a ela i ely pu e ochilini e ha did no con ain
subs an ial in e laye ed se pen ine, since Si and Mg concen a ions a e low. The
FIGURE 3-10. De ail o eplacemen a ound
he M- ype g ain o Y-793321 depic ed in Fig.
3-4e and 3-7 . (a) DF-STEM image showing
he po ous, scaly eplacemen p oduc and
nanoc ys alline domains wi hin. (b) TEM-
EDX X- ay maps o (a) showing he
dis ibu ion o S, O, and C . The la e is
s ongly en iched close o he eac ion
in e ace. (c) SAED ing pa e n and ex ac ed
di ac og am o he eplacemen ma e ial. The
pa e n can be indexed by magne i e and
oili e (o py ho i e – oili e is shown, bu
dis inc ion is no possible in his pa e n due o
low in ensi y o supe s uc u e e lec ions).
86
CHAPTER 3 PYRRHOTITES IN CHONDRITES
occu ence indica es ha ochilini e eplaced he o iginal sul ide g ain du ing aqueous
al e a ion. The C en ichmen close o he eac i e in e ace sugges s local anspo by a
luid du ing aqueous al e a ion o me amo phism, because C is no signi ican ly
con ained in he Fe,Ni sul ides and mus ha e been de i ed om he su oundings o he
g ain.
The ine-g ained po ion o Y-793321 (21F06) con ains monophase pen landi e g ains
o a iable size (se e al µm o less han 1 µm) wi hou associa ed Fe sul ides. They a e
accompanied by magne i e, clinoens a i e, Ca- ich clinopy oxene, Fe- ich se pen ine, and
a calcium sul a e. The la e shows a ib ous ex u e and is di icul o be assigned in
di ac ion pa e ns. Mos p obably, he o iginal phase was gypsum which pa ially
dehyd a ed du ing sample p epa a ion. The sul a e could be an oxida ion p oduc o
sul ides du ing aqueous al e a ion o e es ial wea he ing. Howe e , no ob ious Fe-
bea ing oxida ion p oduc s such as FeOOH polymo phs o e ihyd i e ha e been ound in
he FIB samples.
3.4.3.3. Belgica-7904
In B-7904 we ha e sampled ou si es by FIB: One sul ide-oxide-me al assemblage
(04F01, Fig. 3-5c), and h ee sul ide agg ega es (04F02; 04F03, Fig. 3-5b; 04F04). The
sul ide-oxide-me al assemblage consis s o 1 o 3 µm sized g ains o magne i e, oili e,
and kamaci e (Fig. 3-11a; all iden i ied by SAED). In close associa ion wi h kamaci e,
small g ains o a Ni- ich alloy occasionally occu (i s s uc u e could no be es ablished,
bu likely i is aeni e o awa ui e). No py ho i e was ound. La ge ac ions o in e s i ial
space a e emp y po e space, bu some po es a e illed by anhyd i e, which is well
c ys allized and yields clea zone axis di ac ion pa e ns (Fig. 3-11b). Al hough
e apo i ic con amina ion in An a c ic me eo i es is a conce n (Losiak and Velbel 2011),
he o med phases a e gene ally hyd ous (Velbel 1988), and he good quali y o he
di ac ion pa e n ules ou acuum dehyd a ion o p eexis ing gypsum du ing sample
p epa a ion o obse a ion (see ema ks on Ca sul a e in Y-793321).
The sampled sul ide agg ega es consis o pu e, polyc ys alline oili e wi hou
e idence o exsolu ion o py ho i e. Only a he ma gins o g ain agg ega es in 04F02
weak, addi ional supe s uc u e e lec ions o py ho i e could be de ec ed in SAED
pa e ns (Fig. 3-12a). The e lec ions a e b oad, bu oughly consis en wi h 6C-py ho i e
(N = 6.14±0.14).
87
CHAPTER 3 PYRRHOTITES IN CHONDRITES
FIGURE 3-11. BF-TEM images o sul ides in B-7904 and Y86720. (a) Magne i e- oili e-me al
sphe ule in B-7904 (04F01). Abundan po e space is p esen be ween indi idual g ains. (b) De ail
o sphe ule shown in (a) wi h well c ys alline anhyd i e (Anh) in po e space (Anh SAED pa e n
as inse ). (c) Polyc ys alline oili e in B-7904 (04F04) showing 120° iple junc ions (T o SAED
pa e n as inse ). (d) Polyc ys alline oili e agg ega e in B-7904 (04F03, see Fig. 3-5b) g ading
in o a ine-g ained oili e-oli ine mix u e (lowe le , SAED pa e n as inse ). (e) DF-STEM
de ail image o he ine-g ained oili e-oli ine mix u e in (d). 120° iple junc ions a e abundan
(a ows). ( ) Sec ion ough he euhed al oili e g ain o Y-86720 (20F02) shown in Fig. 3-5d. A
kamaci e g ain and a lu y oili e-oli ine agg ega e occu adjacen o he oili e. The ma ix
con ains pa ches o well c ys alline anhyd i e (Anh SAED pa e n as inse ). (g) De ail o ( )
showing he la ge kamaci e g ain adjacen o oili e (T o SAED pa e n as inse ). A high
disloca ion densi y in he me al g ain con ibu es o i s mo led con as . (h) Py ho i e im on a
la ge oili e g ain in Y-86720 (20F01), see Fig. 3-12b o a SAED pa e n. (i) Fine-g ained
oili e-oli ine mix u e in he lu y o e g ow hs shown in Fig. 3-5e o Y-86720 (20F03).
A a he compac sul ide g ain sampled in 04F04 (Fig. 3-11c) is composed o
polyc ys alline oili e wi hou any de ec able py ho i e o pen landi e. TEM-EDX
indica es he p esence o ew and small Ni-poo Fe me al g ains. The in e nal ex u e
shows abundan iple junc ions and subg ain bounda ies. In sample 04F03 (Fig. 3-11d,e),
88
CHAPTER 3 PYRRHOTITES IN CHONDRITES
compac , polyc ys alline oili e g ades in o ine-g ained oili e, which is in ima ely
in e g own wi h abundan , sub-µm-sized g ains o Fe- ich oli ine (app ox. Fa24 based on
TEM-EDX). In his in e g ow h, polyc ys alline oili e shows equen 120° ( iple
junc ion) g ain bounda ies. Ra ely, app ox. 1 µm-sized Ni-poo , bu ai ly Co- ich Fe
me al g ains occu (~3 a % Ni, ~8 a % Co). The ma ix po ion sampled in 04F02 and
04F03 shows SAED ing pa e ns consis en wi h a composi ion domina ed by sub-µm
sized-oli ine. Ca sul a e, mos likely anhyd i e, occu s as µm-sized, polyc ys alline
pa ches wi hin he ma ix ma e ial. Embedded in silica es and anhyd i e, sub-µm-sized
g ains o a e y Ni- ich alloy occu (abou equal amoun s o Fe and Ni, ~2 a % Co). In
close p oximi y o he sul ide agg ega es, a µm-sized pa ch o Ca ca bona e was ound and
iden i ied as a agoni e by SAED. Alongside he ma gin o he sul ide agg ega e sampled in
04F03 small pen landi e g ains occu , bu mos Ni appea s o be p esen as Ni- ich alloy
g ains wi hin he ma ix.
3.4.3.4. Yama o-86720
F om Y-86720 we ha e ob ained wo FIB samples (20F01; 20F02, Fig. 3-5d) o
euhed al, pla ele -shaped sul ide c ys als wi h adjacen ma ix and one om a pa ial
c ys al wi h adjacen , ine-g ained sul ide-silica e in e g ow hs (20F03, Fig. 3-5e).
Imaging and SAED pa e ns indica e ha he euhed al c ys als a e in e nally pu e oili e.
The oili e c ys als con ain equen subg ain bounda ies and inclusions o Fe,Ni me al
(Fig. 3-11 ,g), indica ing ha hey a e a he pseudomo phs han euhed al single c ys als.
In case o 20F01 and 20F02, na ow, less han100 nm wide ims o NC-py ho i e occu a
he ex e nal ma gins o he oili e (Fig. 3-11h, 3-12b). The N alues de e mined o he
ims a y consis en ly a ound 5.7 (Tab. 3-3). Al hough unce ain ies o indi idual N alues
a e ela i ely la ge, he obse a ions poin o ims ha ha e sligh ly lowe Fe con en s han
hose in B-7904. The ine-g ained sul ide-silica e in e g ow hs in 20F03 we e iden i ied o
be a mix u e o oili e and oli ine, simila o wha is obse ed in B-7904. G ain sizes in
hese agg ega es a e ypically in he o de o a ew 100 nm (Fig. 3-11i). TEM-EDX shows
ha he oli ine is Fe- ich (Fa36-40) and has a mola Fe/Mn a io o abou 44. Many o hese
in e g ow hs show amoeboid ex u es wi h poo ly de ined bounda ies, sugges ing a solid
s a e o ma ion om a local p ecu so . The g ain size o oli ine in hese agg ega es is
la ge han ha o he ma ix and he composi ion is mo e Fe- ich (see below). We did no
ind he e ihyd i e-like ma e ial associa ed wi h o eplacing oili e as desc ibed by
89
CHAPTER 3 PYRRHOTITES IN CHONDRITES
p obably did no e-homogenize a e aqueous co osion had aken place.
TABLE 3-3. TEM-SAED esul s o sul ides.
Me eo i e Sample Zone axis/axes§ q (nm−1)# c* (nm−1)# N = c*/q
Y-791198 98F01 M- ype g ain [100]+[110] 0.286(4) 1.719(6) 6.01(9)
Y-791198 98F01 M- ype g ain [100]+[110] 0.287(4) 1.716(8) 5.98(9)
Y-791198 98F01 M- ype g ain [210]+[1-10] 0.296(12) 1.734(15) 5.86(24)
Y-791198 98F02 M- ype g ain [210]+[1-10] 0.302(6) 1.732(4) 5.74(12)
Y-791198 98F02 M- ype g ain [100]+[110] 0.308(7) 1.733(10) 5.63(13)
Y-791198 98F06 ma ix g ain [210] 0.313(7) 1.715(6) 5.48(13)
Y-791198 98F06 P- ype g ain [100]+[110] 0.475(42) 1.737(22) 3.66(33)
Y-793321 21F01 [210]+[1-10] 0.292(2) 1.735(5) 5.94(4)
Y-793321 21F01 [100]+[110] 0.290(3) 1.738(8) 5.99(7)
Y-793321 21F01 [100]+[110] 0.291(3) 1.738(7) 5.97(7)
Y-793321 21F05 [100]+[110] 0.286(2) 1.713(8) 5.99(5)
Y-793321 21F05 [100]+[110] 0.286(4) 1.710(8) 5.98(9)
B-7904 04F02 oili e im [210] 0.278(6) 1.708(10) 6.14(14)
Y-86720 20F01 oili e im [110] 0.298(4) 1.715(21) 5.76(11)
Y-86720 20F01 oili e im [100] 0.300(8) 1.712(16) 5.71(16)
Y-86720 20F02 oili e im [100] 0.301(8) 1.706(4) 5.67(15)
Y-86720 20F02 oili e im [100] 0.303(6) 1.719(14) 5.67(12)
No e: S anda d de ia ions o leas signi ican digi s in pa en heses. §Two axes gi en in case o
winning. #Each pai o c* and q alues was ob ained om he same SAED pa e n. The gi en
unce ain y ela es o he measu emen p ecision de e mined by measu ing 10 o 15 spo dis ances,
bu accu acy o absolu e alues is no known due o lack o an in e nal s anda d and e o s in
sample heigh , came a leng h, e c. The a io o c* and q is accu a e wi hin gi en unce ain y, as
bo h c* and q a e a ec ed by he same sys ema ic e o s.
Gi en hese obse a ions and da a epo ed by Nakamu a (2005, 2006), he peak
me amo phic empe a u es o Y-793321 su ely c ossed he oili e sol us occu ing a a
maximum empe a u e o 140 °C. As poin ed ou in he in oduc ion, 6C-py ho i e does
no o m immedia ely a he s a o oili e exsolu ion bu o ms om 1C-py ho i e
h ough o de ing o Fe-si e acancies a empe a u es below 100 °C. Gi en ha many
e es ial oili e-bea ing py ho i es, and maybe py ho i es in Y-791198 as well, appea
o ha e been kine ically ozen in he p ocess o low empe a u e equilib a ion (showing
non-in eg al NC s uc u es), sul ides in Y-793321 ob iously equilib a ed well in he
s abili y ield o 6C-py ho i e + oili e. The conside ably coa se in e nal ex u es o
compac M- ype sul ide g ains in Y-793321 compa ed o Y-791198 indica e di e en
he mal his o ies and poin owa d p olonged low- empe a u e he mal annealing o Y-
793321 below 100 °C. Condi e al. (1974) showed ha sel -di usion o Fe in py ho i e is
96

CHAPTER 3 PYRRHOTITES IN CHONDRITES
a he as . A empe a u es below 100 °C, he d i ing o ce ha leads o acancy o de ing
is expec ed o slow down di usion (un o una ely no da a exis in his empe a u e ange),
bu s ill di usi e anspo can easonably be assumed as ela i e o o he geological
ma e ials such as silica es. Hence, based on he da a o Condi e al. (1974) we assume ha
di usion on he sub-µm scale should be possible e en a low empe a u es a ound 0 °C
du ing many hund eds o millions o yea s. The e a e wo ele an scena ios ha could
accoun o he obse ed di e ences in sul ide ex u es o Y-791198 and Y-793321:
Fi s , Nakamu a (2006) iden i ied Y-793321 as a egoli h b eccia and sugges ed sho
du a ion-hea ing by impac s du ing nea -su ace esidence. Fo da k, ch ond i ic ma e ial,
he equilib ium empe a u e o a small sized as e oid o as e oidal su ace should be in he
ange o −50 o −100 °C in he main as e oid bel a 2.8 AU (Bu le 1966) and colde a
la ge dis ance o du ing lowe adia ion ou pu o he young sun. In o de o achie e
p olonged low- empe a u e annealing and coa sening o he py ho i e- oili e mix u e, i
would ha e been necessa y o sus ain egoli h empe a u es abo e he expec ed
equilib ium empe a u e in he main bel by a sui ably high a e o impac s. A he same
ime, peak hea ing du ing episodic impac e en s mus no ha e exceeded empe a u es
abo e he espec i e sol i, in o de o a oid pa ial e-homogeniza ion o e asing o
exis ing exsolu ion ex u e.
In a second scena io, Y-793321 could ha e expe ienced highe long- e m a e age
empe a u es han Y-791198 by ecei ing s onge adia ion hea ing h ough ela i ely
s able o bi al pa ame e s ha b ough he pa en as e oid close o he sun du ing much o
i s li e ime. A a e age sola dis ances in he icini y o he o bi s o Ea h and Ma s he
equilib ium empe a u e o a da k chond i e is expec ed o be a ound 0 °C and, hence,
long- e m esidence in his egion could be esponsible o he di e en ex u al e olu ion
o Y-793321 sul ides.
As poin ed ou by Nakamu a (2006) based on missing Fe-Mg zoning in chond ule
silica es, he peak hea ing o Y-793321, up o supposed 500 °C, was likely ansi ional and
no due o p olonged adiogenic hea p oduc ion. Hence, hea ing mus ha e occu ed while
he ma e ial esided close o he as e oid’s su ace. Hea ing by impac s is ansien wi h
ela i ely apid cooling a es (Wi mann e al. 2010) and is mos ly ega ded as insu icien
o cause long- e m, la ge-scale hea ing o as e oidal bodies (Keil e al. 1997). On he o he
hand, sola hea ing up o he b eakdown empe a u es o phyllosilica es would equi e
close pe ihelion dis ances o less han 0.1 AU (Nakamu a 2005), which appea s
97
CHAPTER 3 PYRRHOTITES IN CHONDRITES
incompa ible wi h a long- e m su i able o bi . This sugges s ha impac -gene a ed hea is
mos likely he explana ion o he high empe a u e me amo phic o e p in , which is
suppo ed by shock me amo phic ea u es (plana ac u es, Nakamu a 2006) obse ed in
Y-793321. Howe e , despi e he low he mal di usi i y o egoli h ma e ial migh
inc ease he e en ion o impac -gene a ed hea , i appea s ques ionable whe he he a e o
epea ed impac s could ha e been high enough o keep he long- e m a e age egoli h
empe a u e in a easonable ange o allow coa sening o sul ides in Y-793321 ela i e o
Y-791198. A long- e m esidence o he Y-793321 pa en body in he icini y o he o bi s
o Ea h and Ma s and co esponding highe su ace equilib ium empe a u es appea o be
be e explana ions o his phenomenon.
3.5.4. High G ade Pa en Body Me amo phism
The oili e-me al assemblages o B-7904 and Y-86720 a e unlike he sul ides and
me als obse ed in CM chond i es s udied he e and epo ed elsewhe e. In e ms o sul ide
mine alogy, he euhed al, me al-bea ing oili e pseudomo phs seen in Y-86720 a e he
mos elling e idence o s ong me amo phic o e p in o hese ocks. We in e p e hem
o ep esen he eplacemen o o me euhed al py ho i e c ys als, simila o hose known
om CI chond i es. Assuming he o iginal py ho i e o ha e been Fe7S8 (x = 0.125) as
obse ed in CI chond i es (Be ge e al. 2011), he ollowing eac ions desc ibe he
p ocess:
Fe1-xS(s) → (1-x)FeS(s) + (0.5x)S2(g) → (1-x)Fe(s) + 0.5S2(g) (3-5)
The eac ions a e d i en o he p oduc sides by low S2 and he oili e-me al
assemblages in B-7904 and Y-86720 essen ially cons ain he sul u ugaci y a peak
me amo phic empe a u es o ha o he IT bu e . As ou lined in he in oduc ion, he
s able coexis ence o Fe oxides and py ho i e couples S2 and O2. Figu e 3-1b shows O2
isoba s o coexis ing magne i e (Whi ney 1984). Isoba s o o he coexis ing oxidic Fe
mine als (including wüs i e) can be calcula ed acco dingly. In S2-T space, he
in e sec ions o isoba s o equal O2 o wo pai s o py ho i e-oxide assemblages de ine
he cu es o join S2- O2 bu e s, along which bo h ugaci ies a e ixed a gi en
empe a u e. The i on-magne i e-py ho i e (IM-Po) and i on-wüs i e-py ho i e (IW-Po)
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CHAPTER 3 PYRRHOTITES IN CHONDRITES
bu e s coincide wi h he IT bu e , because he sul ide in equilib ium wi h me al is always
s oichiome ic oili e. The magne i e-wüs i e-py ho i e (MW-Po) bu e becomes ele an
a empe a u es abo e 570 °C.
Despi e wüs i e is no expec ed o be a s able phase in associa ion wi h magnesian
silica es and will likely dissol e in hem (depending on SiO2 ac i i y), he bu e eac ion
can app oxima ely cons ain he me amo phic empe a u e, a which magne i e becomes
ins able along he IT bu e line. Fo uni y ac i i y o FeO, he MW-Po line in e sec s he
IT line in an in a ian poin a app ox. 572 °C, co esponding o an S2 o −12.7 o −13.1
log uni s (depending on he sou ce o S2 da a; Toulmin and Ba on 1964, Rau 1976) and
an O2 o −25.8 log uni s. FeO ac i i ies o less han one s ongly shi he in e sec ion
owa d lowe empe a u es (e.g., ~400 °C o aFeO = 0.6). Tex u ally, especially wi h
ega ds o sul ide mo phology, Y-86720 bea s much esemblance o CI chond i es, which
ca y abundan magne i e. E en i he p ecu so mine alogy was mo e CM-like, magne i e
would ha e been a ubiqui ous accesso y phase. I we in e p e he comple e lack o
magne i e in Y-86720 o be he esul o educ ion o FeO and assume ha bo h Y-86720
and B-7904 ini ially had simila FeO and SiO2 ac i i ies in hei silica e po ions, hen he
ollowing scena io a ises: Y-86720 has expe ienced peak me amo phic empe a u es abo e
he s abili y limi o magne i e, while B-7904 was subjec ed o lowe empe a u e a
condi ions in a o o magne i e conse a ion. This cons ains he peak me amo phic
empe a u e o B-7904 o less han 570 °C and sugges s S2 and O2 o ha e been below
hose alues gi en abo e o he in a ian poin a which oili e, i on, magne i e, and
wüs i e coexis . The empe a u e es ima e compa es well o he ange de i ed by Zolensky
e al. (1991), bu is lowe han he empe a u es sugges ed by Akai (1990, 1992).
The 6C-like py ho i e occu ing as ims on oili e in B-7904 and Y-86720 is
appa en ly no in equilib ium wi h he coexis ing me al, since Fe-de iciency in NiAs-
s uc u ed sul ide would no be allowed by he low S2 ha led o he o ma ion o Fe,Ni
me al. Figu e 3-1a shows ha a composi ion o Fe0.917S (x = 0.083), co esponding o 6C-
py ho i e, o ms a S2 o abou 5 o 8 log uni s abo e he IT bu e . Howe e , since any
composi ion o med be ween he x = 0 ( oili e) and x = 0.083 isople hs would decompose
in o oili e and 6C-py ho i e below 100 °C, i canno be uled ou ha he Fe-de icien
oili e ims o med in his in e media e egion. Clea ly, he ims o med a ele a ed S2
ela i e o he IT bu e , a which he bulk o he sul ides equilib a ed. We in e p e he
99
CHAPTER 3 PYRRHOTITES IN CHONDRITES
o ma ion o ims o ep esen a la e-s age, low- empe a u e eac ion du ing cooling when
S2 was no longe in equilib ium wi h he oili e-me al assemblage. A his s age low
amoun s o pos -me amo phic, hyd ous luids migh ha e been in ol ed in he al e a ion
as documen ed by hea sensi i e mine als such as calci e and a agoni e. The modynamic
calcula ions show ha anhyd i e is no a s able phase unde condi ions o oili e
o ma ion. Figu e 3-1b shows S2 isople hs o an assemblage in ol ing py ho i e,
magne i e, anhyd i e, and CaO (dissol ed in silica es). The loca ion o isople hs is gi en
by he in e sec ions o O2 isoba s o eac ion 3-3 and co esponding isoba s o he
eac ion:
CaSO4(s) → CaO(ss) + 0.5S2(g) +1.5O2(g) (3-6)
A aCaO = 1 he isople h is loca ed closely o he FMQ-Po bu e o Eggle and Lo and
(1993), lying jus below he x = 0.083 isople h o 6C-py ho i e. Lowe CaO ac i i ies
shi he anhyd i e isople h owa d highe S2 in o he ield, whe e 4C-py ho i e (x =
0.125) would be expec ed o o m. Hence, a ela i ely high CaO ac i i y (possibly
documen ed by calci e/a agoni e o ma ion) and S2 jus abo e he FMQ-Po bu e ,
condi ions would ha e been a o able o o ming bo h anhyd i e and he Fe-de icien ims
on oili e. This clea ly indica es a wo-s age e olu ion o he obse ed assemblage – a
peak me amo phic s age and a e og ade, maybe hyd ous, s age.
3.5.5. Rela ions among Me amo phosed and P is ine CM/CI Chond i es
The oxygen iso opic composi ions o B-7904 and Y-86720 a e dis inc om CI and CM
chond i es, bu could be ela ed o CI chond i es h ough mass-dependen ac iona ion
(Mayeda and Clay on 1998). Clay on and Mayeda (1999) sugges ed an iso opic model
in ol ing mixing be ween anhyd ous ock and a wa e ese oi and poin ou possible
gene ic ela ionships be ween CI and CM chond i es. These could ha e been o med by
mixing along a common o e y simila mixing line, bu we e subsequen ly p ocessed a
di e en empe a u es and wa e / ock a ios. The ela ionships a e exempli ied by he
exis ence o anomalous, ansi ional CM/CI-like membe s, such as he me eo i es Bells
and Essebi, which no only ha e ansi ional oxygen iso opic composi ions, bu also
con ain abundan CI-like magne i e.
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CHAPTER 3 PYRRHOTITES IN CHONDRITES
F om he pe spec i e o sul ide mine alogy, he p e-me amo phic p ecu so s o B-7904
and Y-86720 migh ha e been simila ansi ional cases. Assuming ha he 17O- and 18O-
ich composi ions a e due o dehyd a ion and e olu ion along an expec ed slope 0.5 line,
he p ecu so p obably had CI-like oxygen iso opic a ios. On he o he hand, he ine-
g ained oili e-oli ine in e g ow hs obse ed in Y-86720 and B-7904 sugges he o me
p esence o in e laye ed ochilini e-se pen ine agg ega es, which he mally b oke down
in o oili e, as sugges ed by Tomeoka e al. (1989b), plus oli ine. Because he sub-µm-
sized, highly dispe sed oli ine g ains unlikely o med as a esul o exsolu ion, and
amoeboid agg ega e shapes exclude c ys alliza ion om a sul ide-silica e mel , he e a e
ha dly al e na i es o assuming an ini ially uni o m, sul ide- and silica e- ich mix u e. The
possibili y ha sul ide in il a ed he oli ine- ich ma ix du ing he e og ade s age
appea s possible bu emo e, because his sul ide should ha e been py ho i e wi h li le
ex u al equilib a ion. Ins ead, we ind ex u ally ai ly equilib a ed oili e wi h abundan
iple junc ions and ela i ely la ge oli ine g ains unlike hose in he ma ix (e.g., Fig. 3-
5 ). The in e ed p esence o ochilini e indica es ha he p ecu so mine alogies o bo h
me eo i es migh ha e been indeed CM-like, since sul ide-bea ing in e laye mine als a e
gene ally absen in CI chond i es. The p ese a ion o p ima y silica es in B-7904 and Y-
86720 also ex u ally suppo s a a he weakly al e ed, CM-like p e-me amo phic
mine alogy, while p ese ed euhed al sul ide mo phologies in Y-86720 indica e CI
simila i ies.
3.6. Conclusions
The sul ide mine alogies o CM and CI chond i es and hei anomalous ela i es p oo
o be e y di e se and eco d complex e olu iona y his o ies. In CM2 chond i es Y-
791198 and Y-793321, he NC-py ho i e- oili e-pen landi e associa ion ound in M- ype
g ains indica es high empe a u e o ma ion om a once homogeneous MSS. This is
inconsis en wi h pa en body aqueous al e a ion and s ongly poin s o p ocessing in he
sola nebula. An assessmen o nebula condi ions ha led o he o ma ion o he MSS
p ecu so s, ins ead o he usual Ni-poo oili e, is di icul due o he lack o knowledge
abou he bulk composi ion o now exsol ed and highly he e ogeneous sul ide g ains. 4C-
py ho i e in associa ion wi h magne i e and pen landi e in P- ype sul ide agg ega es
possibly poin s o a ela i ely oxidizing nebula en i onmen du ing sul ida ion and
o ma ions o hese peculia agg ega es.
101

CHAPTER 3 PYRRHOTITES IN CHONDRITES
The mic os uc u e o complex sul ide g ains can u he add in o ma ion on low
empe a u e cooling a es and he mal e olu ion, sugges ing ha Y-793321 expe ienced
highe long e m a e age empe a u es han Y-791198 in he < 100 °C empe a u e egime.
TEM s udies in combina ion wi h kine ic modelling o he exsolu ion p ocess could
p o ide be e cons ain s on ac ual cooling a es. Howe e , while da a on di usi i y in
diso de ed, high- empe a u e py ho i es is a ailable, da a on low empe a u e di usion
a es in o de ed py ho i es is s ill needed o such calcula ions. Also de ailed knowledge
abou low empe a u e phase ela ions in he Fe-Ni-S sys em is desi able, speci ically
add essing he ela ionships be ween di e en py ho i e a ian s below 100 °C and he
solubili y o Ni in hem. Ou obse a ions o wo-s age pen landi e exsolu ion in Y-791198
sul ides sugges a dec ease in Ni solubili y du ing he oili e exsolu ion and/o he
subsequen 1C- o NC-py ho i e o de ing. Sub-µm pen landi e exsolu ion in Fe- ich
py ho i e (x < 0.083) migh he e o e no necessa ily cons ain high empe a u e
p ocessing nea he classical pen landi e sol us, bu a he poin o p ocesses in he 100 o
140 °C ange.
Co osion o NC-py ho i e, oili e, and pen landi e in M- ype g ains o Y-793321 is
sca ce, bu indica i e o ins abili y o hese phases du ing aqueous al e a ion. The
co osion p oduc likely was ochilini e, which con e ed o magne i e plus oili e du ing
he he mal o e p in on Y-793321.
The highly me amo phic Belgica g ouple me eo i es Y-86720 and B-7904 show oili e
as dominan sul ide phase wi hou any esemblance o sul ides in p is ine o lowly
me amo phosed CM2 chond i es. In bo h me eo i es, oili e coexis s wi h Fe,Ni me al
indica ing peak me amo phism a S2 o he IT-bu e unde s ongly educing condi ions.
The absence o magne i e in Y-86720 sugges s c ossing in o he wüs i e ield and indica es
a highe me amo phic g ade han B-7904, in which magne i e is p ese ed. The
me amo phic condi ions o B-7904 can be cons ained o T < 570 °C, S2 < −13.1 and O2
< −25.8 log uni s. T oili e in Y-86720 and B-7904 shows ims o 6C-like py ho i e and
he ma ix o bo h me eo i es con ains anhyd i e. Bo h phases a e no s able unde he
condi ions o he IT-bu e and mus ha e o med du ing cooling a e he me amo phic
e en .
Tex u ally, he Belgica gouple me eo i es a e e y di e se, bu obse a ions on sul ide
mine alogies link hem among each o he and o CM and CI chond i es. In Y-86720
euhed al, pla ele shaped oili e pseudomo phs occu akin o py ho i e c ys als seen in CI
102
CHAPTER 3 PYRRHOTITES IN CHONDRITES
103
chond i es. In Y-86720 and B-7904 ex emely ine-g ained and closely in e g own oili e-
oli ine mix u es occu , which mos p obably o igina ed om he b eakdown o ochilini e-
se pen ine in e g ow hs ypically p esen in CM chond i e. Especially in case o Y-86720,
hese obse a ions imply an in e media e mine alogical composi ion o he p ecu so ock
be ween CM and CI chond i es.
3.7. Acknowledgemen s
We g a e ully acknowledge sample loan by he Na ional Ins i u e o Pola Resea ch
(NIPR) o Japan and inancial suppo by he Leibniz p og am o he Ge man Resea ch
Founda ion (DFG; LA 830/14-1 o F.L.) and he ENB p og am o he Ba a ian S a e
Minis y o Sciences, Resea ch and he A s ( o D.H.).
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
CHAPTER 4 Oxida i e Dissolu ion o 4C- and NC-Py ho i e: In insic Reac i i y
Di e ences, pH Dependence, and he E ec o Aniso opy
by Dennis Ha ies1,2*, Kilian Pollok2, and Falko Langenho s 2
1Baye isches Geoins i u , Uni e si y o Bay eu h, D-95440 Bay eu h,
Ge many. 2Ins i u ü Geowissenscha en, F ied ich-Schille -Uni e si ä
Jena, Ca l-Zeiss-P omendae 10, D-07745 Jena, Ge many.
*Co esponding au ho . Email: dennis.ha ies@uni-bay eu h.de
4.1. Abs ac
We ha e conduc ed oxida i e dissolu ion expe imen s on monoclinic 4C-py ho i e and
‘hexagonal’ NC-py ho i e in aqueous H2O2/H2SO4 and FeCl3/HCl media a pH be ween
1.8 and 2.9 using polished su aces o single c ys als. Quan i ica ion and de ailed
cha ac e iza ion o he eac ion in e aces has been accomplished by con ocal 3D
opome y and ansmission elec on mic oscopy (TEM) in conjunc ion wi h ocused ion
beam (FIB) p epa a ion. C ys allog aphically cohe en in e g ow hs o 4C- and NC-
py ho i e in a single sample allowed unambiguous iden i ica ion o s ong in insic
eac i i y di e ences be ween he wo closely ela ed phases. On {110} aces in he H2O2
medium a 35 °C and pH below 2.70, NC-py ho i e (N ~4.85) eac s abou 50 o 80 %
as e han 4C-py ho i e. Abo e pH 2.70 he beha io in e s and 4C-py ho i e dissol es
as e , while o e all eac ion a es d op d as ically by up o wo o de s o magni ude.
Because he wo py ho i e phases show only ma ginally di e en Fe/S a ios bu
subs an ial di e ences in s uc u al complexi y wi h ega ds o acancy o de ing, we
a ibu e he eac i i y di e ences o s uc u ally con olled p ocesses a he mine al-wa e
in e ace. The ansi ion a pH 2.70 is close o he epo ed isoelec ic poin o py ho i e.
We a ibu e he pH dependen changes in eac ion a es and beha io s o
p o ona ion/dep o ona ion o su ace sul hyd yl g oups and ela ed changes in specia ion
and bonding mode o eac i e oxygen species a he mine al in e ace. A pH < 2.70 we
ind elemen al sul u as a equen eac ion p oduc in H2O2 and FeCl3 media, indica ing
incomple e sul u oxida ion. Abo e pH 2.70, elemen al sul u was no ound in H2O2
expe imen s (no da a o FeCl3). Ou esul s show ha he e ec s o c ys al aniso opy a e
s ong and di ec ional p e e ence o dissolu ion changes a he pH 2.70 ansi ion poin as
well, leading o complex sub-µm-scale ex u al de elopmen a he eac ion in e aces
h oughou he pH ange s udied. High esolu ion TEM imaging o FIB c oss sec ions
h ough eac ed mine al su aces show c ys alline py ho i e up o he eac ion in e ace
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
and he absence o signi ican non-equilib ium laye s o S-en iched (poly)sul ides.
4.2. In oduc ion
4.2.1. Gene al In oduc ion
Py ho i e comp ises a g oup o non-s oichiome ic i on monosul ides (Fe1-xS), which
occu as equen accesso y phases in c us al ocks o Ea h (Roche e e al. 1990) and a e
p esen in la ge amoun s in many base and noble me al o e deposi s (e.g., Bowles e al.,
2011). Despi e hei simple and e y simila composi ions, py ho i es show a la ge
a iabili y in s uc u es and magne ic p ope ies (e.g., Schwa z and Vaughan 1972;
Benne and G aham 1980). The wea he ing o py ho i e unde in luence o a mosphe ic
oxygen p oceeds app oxima ely 20 o 100 imes as e han ha o py i e (Nicholson and
Scha e 1994) and can gene a e acidic mine d ainage (AMD) and concu en elease o
hea y me als in o he en i onmen (Belzile e al. 2004). Reac i i y di e ences exis
among di e en a ie ies o py ho i e, bu a comp ehensi e pic u e o he sys ema ics o
i s wea he ing beha io is s ill lacking (Belzile e al. 2004). The e o e, he unde s anding
o he in insic di e ences in chemical beha io o py ho i es is a c ucial pa in
e alua ing and modeling he en i onmen al impac o mining py ho i e-bea ing o es.
Because biological ac i i y o chemoli ho ophic mic obes is known o enhance eac ion
a es and plays a signi ican ole in he chemical e olu ion o mining en i onmen s (e.g.,
Schippe s and Kock 2009; Gunsinge e al. 2006), such unde s anding is needed o esol e
he con ibu ion o mic obiological communi ies o py ho i e wea he ing. On he
echnological side, e icien mine al p ocessing depends on well cons ained mine al
p ope ies. Becke e al. (2010) ecen ly showed ha di e en a ie ies o py ho i e
pe o m signi ican ly di e en in lo a ion expe imen s. The di e ences a e a ibu ed o
di e en in insic suscep ibili ies o su ace oxida ion.
4.2.2. Mine alogy o Py ho i e
A ambien condi ions py ho i e occu s in h ee majo o ms: oili e (s oichiome ic
FeS), 4C-py ho i e (Fe0.875S o Fe7S8), and NC-py ho i e (app ox. Fe0.88-0.92S). All o ms
a e based on a laye ed NiAs- ype subs uc u e, on which supe s uc u es a e imposed by
o de ing o Fe-si e acancies in he non-s oichiome ic py ho i es. In 4C-py ho i e Fe
si e acancies a ange highly egula and supe pose a monoclinic supe s uc u e by s ic
al e na ion o illed and pa ially acan Fe laye s (Be au 1953; Powell e al. 2004). The
105
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
FIGURE 4-2. (a-d) Expe imen ypes and expe imen al p ocedu e applied o single sample as-
semblies (SSA) and mul i-sample assemblies (MSA). (a) SSA is a polished single c ys al
(EUL1inL) shown a e h ee expe imen s (s ipes wi h expe imen numbe s, see Tab. 4-2). (b)
MSA consis o 3 mm cylinde s o py ho i e in di e en o ien a ions se in a 25.4 mm PMMA
holde . (c+d) Expe imen al p ocedu e. (1) A e polishing. Due o he ha dness di e ence be-
ween py ho i e and PMMA he sul ide su ace is cu ed (exagge a ed he e). (2) A e expe i-
men al al e a ion. Py ho i e has dissol ed and al e a ion phases ha e p ecipi a ed. Typically,
enches de elop along he edges o he masked a eas (see ex ). (3) A e emo al o al e a ion
laye s and masks. Fo me ly masked py ho i e se es as e e ence le el o he de e mina ion o
e ching dep hs (Δh). Fo MSA samples pa abolic e e ence le els we e used o accoun o su ace
cu a u e. (e-g) Visual appea ance o MSA samples a e expe imen s (a ow o e e ence). (e)
A e 651 hou s in FeCl3+HCl solu ion (0.01 mol/L Fe3+, pH 1.80−1.92) a 30 °C. Yellowish su -
aces con ain abundan elemen al sul u and Fe oxyhyd oxides, da k su aces eac ed li le, excep
EUL {110}, which showed enhanced oughness and su ace pi ing (c . Fig. 4-4e). ( ) A e 13
hou s in H2O2+H2SO4 solu ion (0.1 mol/L H2O2, pH 2.05) a 35 °C. Whi e and g ayish c us s a e
elemen al sul u wi h li le Fe oxyhyd oxide, da k a eas had been masked. {hk0} su aces eac ed
s onge han (001) su aces, he la e showing hinne sul u c us s. (g) A e 44 hou s in
H2O2+H2SO4 solu ion (0.1 mol/L H2O2, pH 2.88) a 35 °C. S ong p ecipi a ion o Fe oxyhyd ox-
ides occu ed and masking de e io a ed due o solu ion c eeping unde nea h. (001) su aces e-
ac ed s onges unde hese condi ions.
4.3.2. Sample P epa a ion
The idiomo phically de eloped, 2-3 cm sized c ys als o EUL and DAL we e cu
acco ding o ex e nal mo phology using a slow speed diamond wa e ing saw. Bo h
112

CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
c ys als we e six-sided p isms wi h simple basal aces. Th ee mu ually pe pendicula
sec ions we e ob ained pa allel o planes o he hexagonal o ms (001), {110}, and {100}.
P ecise iden i ica ion o o ien a ions was accomplished by use o elec on back-sca e
di ac ion (EBSD). Fo his pu pose we used a HKL No dlys came a a ached o a LEO
1530 FEG SEM (25 kV/ ~4 nA).
F om he ob ained slabs cylinde s o 3 mm diame e and 2 o 5 mm leng h we e
ob ained using a Ga an 601 ul asonic disc cu e . The cylinde s we e hen moun ed in o 3
mm holes o 25 mm diame e PMMA discs wi h each disc ecei ing a o al o 6 py ho i e
samples, comp ising each o he h ee o ien a ions o EUL and DAL (Fig. 4-2b). This
mul i sample assembly (MSA) assu ed iden ical su ace inish o all indi idual samples
a e polishing. Al e na i ely, la ge c ys al slabs we e moun ed in 25 mm Buehle
phenolic ing o ms (single sample assembly, SSA). All moun ing in ol ed use o
chemically esis an S ue s EpoFix epoxy esin cu ed a oom empe a u e.
P epa a ion o EBSD analysis and la e exposu e o eac i e solu ions was done using
s epwise lapping and polishing: Rough we sanding, 1200 SiC lapping, 4000 SiC o 3 µm
diamond polishing, and inal chemomechanical polishing using S ue s OP-U colloidal
silica suspension (2 o 5 hou s). The chemomechanical polishing s ep se es o educe
su ace damage ob ained du ing p e ious polishing s eps. Su ace damage o igina es om
mechanical s esses induced by polishing g i and is cha ac e ized by high disloca ion
densi ies ex ending down o se e al µm in o he ma e ial (e.g., Nou uzi-Kho asani e al.
1990). This damage s ongly de e io a es EBSD pa e ns, because he escape dep h o
cohe en ly sca e ed elec ons is limi ed o he uppe mos 10 o 50 nm o he sample,
which a e p ac ically amo phous. Such highly diso de ed laye s likely change he
physicochemical su ace p ope ies and he e o e, we gene ally used OP-U polished
samples in ou eac i i y expe imen s. Because colloidal silica ends o adhe e o he
sul ide su aces and ca bon coa ing had o be emo ed, inal cleaning using 250 nm
diamond suspension was occasionally needed and applied manually on so polishing clo h
o a ew seconds. TEM c oss sec ion h ough such samples con i med low disloca ion
densi ies no ex ending below he uppe mos 200 nm, which is small compa ed o ypical
e ching dep hs o se e al µm achie ed in his s udy.
In o de o de i e absolu e e ching dep hs om 3D su ace opome y we applied
masking o some pa s o he sul ide su aces du ing mos uns (Fig. 4-2). Clea , sel -
adhesi e ape and Kap on ape cu sha ply by a azo blade we e ound o be mos sui able.
113
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
Di e se lacque s es ed u ned ou o be insu icien due o dissol ing in he medium o
allowing luid o leak unde hem due o capilla y o ce. The exposed a eas we e
app oxima ely hal he a eas o co e samples in MSAs and s ipes o 1 o 2 mm wid h and
1 o 1.5 cm leng h in SSAs.
4.3.3. Expe imen al Se up and Condi ions
Dissolu ion expe imen s on polished su aces we e conduc ed unde a a ie y o
chemical condi ions (Tab. 4-2). Two uns in ol ing e ic i on as oxidan commenced in a
0.01 mol/L e ic chlo ide (FeCl3) solu ion wi h ini ial pH adjus ed o 1.8-2.0 using
hyd ochlo ic acid. The du a ion o each un was app ox. 650 hou s (~27 days) du ing
which he empe a u e was held cons an a 30 o 35 °C. The eac ion essel o hese
expe imen s was a wa e jacke ed bo osilica e glass eac o wi h a olume o 150 mL. The
sample moun was held in place by a Te lon space and he solu ion was s i ed
magne ically. Tempe a u e was kep cons an (±1 °C) by a Haake Fisons DC1 he mos a ic
ci cula o and moni o ed by a luo opolyme coa ed NTC empe a u e p obe a ached o a
WTW pMX 3000 pH/ion me e . The oxida ion educ ion po en ial (ORP) was eco ded on
he same uni using a Me le -Toledo InLab Redox-L Ag/AgCl elec ode. The pH in he
eac o was measu ed in e mi en ly wi h a Me le -Toledo InLab Rou ine P o-L elec ode
which was calib a ed agains pH 2 and pH 4 e e ence bu e s. Gene ally, he pale yellow
Fe3+ solu ion u ned o ange du ing he i s 20 o 40 hou s o hea ing and p ecipi a ed
colloidal akaganei e,
β
-FeO(OH,Cl), was con i med by TEM. The p ecipi a ion was
accompanied by a dec ease in measu ed ORP which d opped om ini ially 910 mV
(s anda d hyd ogen elec ode, SHE) o a ound 890 mV (SHE). The e o e, he sul ide
sample was no added o he solu ion un il i had s abilized. The p ecipi a ion o Fe
oxihyd oxide limi ed he accessible pH ange o alues below 2, as a la ge pH s ong
p ecipi a ion would occu . Due o he long du a ion o almos one mon h no masking was
applied, because p io es expe imen s showed ha solu ion ine i ably c ep unde he
masks i exposed o longe pe iods o ime.
As an al e na i e oxidan we used a solu ion o 0.1 mol/L hyd ogen pe oxide (H2O2)
acidi ied by sul u ic acid (H2SO4). This o e ed he possibili y o a y pH in a wide ange
(1.8 o 2.9) as pe mi ed by Fe3+, and allowed apid eac ion a es and he e o e many uns
(including epe i ions) and s able masking. Also, his app oach kep he chemical sys em
ela i ely simple wi h a minimum o p ecipi a ing phases. Because eac ions we e apid,
114
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
esul ing in e ching dep hs o se e al µm wi hin 3 o 14 hou s a 35 °C, he expe imen s
we e conduc ed wi hou in si u moni o ing in 250 mL E lenmeye lasks illed wi h 200
mL solu ion and shaken a 180 pm in empe a u e con olled mic obiological incuba o s
(New B unswick Scien i ic Inno a 42 and Excella E24). pH was checked be o e and a e
each un and gene ally did no change signi ican ly (< 0.05 uni s). In addi ion o
expe imen s using 0.1 mol/L H2O2 and sul u ic acid only, some uns we e conduc ed wi h
he addi ion o 0.01 o 0.1 mol/L FeSO4 o 0.7 mol/L 2-p opanol in o de o es o
possible de ia ions in he eac ion beha io (see sec ion 4.4.2.2.). Fo he same pu pose
one SSA expe imen was conduc ed using a pu e 0.05 mol/L solu ion o Fe2(SO4)3 (i.e.,
0.1 mol/L Fe3+) a pH 1.80-1.85 wi h no addi ion o H2O2 o H2SO4 (highe pH no
a ainable).
4.3.4. Analy ical Me hods
A e expe imen al uns samples we e washed wi h demine alized wa e and d ied.
Reac ion p oduc s on he py ho i e su aces we e checked by Raman spec oscopy using a
Jobin Y on Lab am mic o-spec ome e equipped wi h a 632.8 nm He-Ne lase . Lase
powe was adjus ed o a le el which a oided isible bu n ma ks on he su aces.
Selec ed samples we e imaged wi hou conduc i e coa ing in a FEI Quan a 3D FEG SEM
ope a ed in low acuum mode (0.6 o 1.2 mba ) a 5 keV elec on ene gy. Samples we e
hen leached wi h cyclohexane in o de o emo e possibly p esen elemen al sul u and
subsequen ly ca bon coa ed o u he imaging using he FEI Quan a 3D and a LEO 1530
FEG SEM. The emo al o sul u was necessa y due o i s ola ili y in high acuum and
i s obs uc ion o he eac ed sul ide su ace.
Fo TEM sample p epa a ion we applied he FIB me hod p o ided by he FEI Quan a
3D FEG dual beam sys em (Ga+ ions). Because he p ese a ion o he uppe mos sample
su ace is c ucial o a meaning ul TEM s udy, he sample was ei he coa ed wi h a e y
hick ca bon coa ing (~50 nm) o locally p o ec ed by elec on beam assis ed pla inum
deposi ion (5 keV elec on ene gy) be o e he ion beam was u ilized o apply he usual
p o ec i e pla inum s ap. Fo exca a ion o enches a ound he a ge ed TEM oil si es
ion beam cu en s om 50 nA down o 3 nA a 30 keV ion ene gy ha e been used,
dec easing as he p ospec i e sample si e was app oached. Cleaning be o e li -ou was
applied using a 30 keV/1 nA beam. The emaining 0.5 o 1 µm hick lamellae we e hen
cu ee, ex ac ed wi h an Omnip obe ungs en needle mic omanipula o , and a ached o a
115
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
pos - ype coppe TEM g id. Final hinning hen p oceeded using beam cu en s o
ypically 300 pA, 100 pA, and 50 (o 30) pA a 30 keV ene gy. In o de o minimize Ga
implan a ion and ion beam induced s uc u al damage he las polishing s ep usually
in ol ed a beam ene gy o 5 keV and a cu en o 80 pA o lowe . A hese condi ions he
s opping dep h o Ga+ ions lies in he o de o a ew nm a g azing beam incidence ela i e
o he oil su ace (e.g., Rubano and Mun oe 2004; Mille and Russell 2007). Hea ing
e ec s du ing FIB p epa a ion o Fe sul ides a e mos ly negligible (Wozniakiewicz e al.
2011).
Fo imaging and selec ed a ea elec on di ac ion (SAED) we used a Philips CM20
FEG TEM ope a ed a 200 kV and equipped wi h a The mo No an Ge EDS de ec o . EDS
measu emen s and X- ay mappings we e acqui ed in scanning TEM (STEM) mode.
FIGURE 4-3. Quan i a i e 3D su ace opome y. (a) A e 13 hou s a pH 2.05 in H2O2+H2SO4
and subsequen cleaning (see ex ). Lamellae and egions o 4C-py ho i e clea ly s and ou
agains he NC ma ix. The a ow ma ks a modes ly de eloped ench along he o me mask
edge. (b) Exempla y heigh dis ibu ion ob ained om he squa e egion ma ked in (a). The le el
is gi en ela i e o he masked/unal e ed e e ence plane.
3D opome y o masked samples was ob ained wi h a Nano ocus µsu cus om
con ocal mic oscope. The sample su ace is he eby illumina ed by a g een ligh emi ing
diode while a piezo-d i en mic oscope objec i e scans h ough a se ies o ocal dis ances.
The inse ion o a mul i-pinhole (Nipkow) disc in he op ical pa h e ec i ely limi s he
in ensi y ecei ed a he CCD de ec o o a e y na ow ocal dep h ange, allowing he 3D
econs uc ion o he sample’s su ace opog aphy om he ob ained image s ack (Fig. 4-
3a). The achie able heigh esolu ion can be as good as a ew ens o nm on low oughness
su aces. Fo ou wo k we used 20× (NA 0.45, WD 3.1 mm) and 100× (NA 0.90, WD 1.0
116
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
mm) objec i es, yielding ields o iew o 800×800 µm2 and 160×160 µm2, espec i ely.
In some cases, se e al adjacen heigh images we e s i ched in o de o enla ge he co e ed
a ea. The mean heigh di e ence Δh be ween he o iginal su ace p ese ed unde he
mask and he al e ed sul ide su aces yields he amoun o eac ed ma e ial and he linea
eac ion a e in e ms o eac ed moles o Fe:
x)1(
Po
Po −
Δ
=M
h
ρ
is he eac ion ime,
ρ
Po is he densi y o py ho i e, and MPo is he mola mass (in e ms
o he Fe1-xS o mula). In his ela ion he a e is ully ep esen ed by he mean heigh
di e ence and independen o he exposed (geome ic) a ea (c . As a e al. 2008).
Meaning ul measu emen s o Δh equi e ha any coa ings on he eac ed su aces mus be
emo ed. This was done using cyclohexane o emo al o sul u and Walle ’s solu ion
(0.25 mol/L isodium ci a e, 0.1 mol/L sodium hyd ogen ca bona e, 0.1 mol/L sodium
di hioni e in wa e ) o emo al o Fe oxyhyd oxides when p esen . Walle ’s solu ion has
close o neu al pH (app ox. 7.45) and is s ongly educing (app ox. −460 mV SHE),
con e ing Fe3+ in o Fe2+ which is complexed by ci a e ligands. The sample was
imme sed in o he solu ion o a ew minu es unde ul asonic agi a ion a oom
empe a u e. Inspec ion o he o iginal, polished py ho i e su ace indica ed no de ec able
e ching e ec on he sul ide du ing he sho exposu e.
The ob ained heigh images we e p ocessed using he Gwyddion analysis so wa e
(Nečas and Klape ek 2012). P ocessing in ol ed heigh calib a ion by le eling he o iginal
su ace benea h he emo ed mask o ze o heigh and p oducing dep h his og ams o he
eac ed a eas. In mixed 4C/NC samples he ob ained dep h dis ibu ions we e ypically
bimodal due o heigh di e ences be ween he 4C and NC po ions (Fig. 4-3b). The
dis ibu ions we e hen p ocessed using he Fi yk peak i ing p og am (Wojdy 2010) in
o de o de e mine a e aged dep hs and app oxima e sp eads o he indi idual dep h
componen s con ibu ion o he su ace opog aphy. Fo i ing we used Pea son ype VII
and logno mal unc ions (usually no mo e han wo pe i ) which gene ally p o ided he
bes app oxima ion o he dep h dis ibu ions. Fi s we e op imized in o de o ob ain good
i ing in he a eas o peak maxima, while he low equency bases o he dis ibu ions
we e conside ed o be o seconda y impo ance due o he possible con ibu ion o su ace
117

CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
i egula i ies like c acks, inclusions, sc a ches o dus pa icles, leading o locally
anomalous e ching beha io .
Du ing he quan i a i e opome ic e alua ion o expe imen s wo di icul ies became
appa en . (i) In almos all expe imen al uns ela i ely deeply e ched enches de eloped
along he bounda y be ween he masked and exposed sul ide su aces. These enches
de eloped benea h he ou e mos po ion o he masking ape, whe e solu ion was able o
c eep unde he p o ec i e co e . In consequence, he di ec measu emen o he s ep
heigh along he masking bounda y was usually di icul . Howe e , in case o he SSA he
masked su ace was plane enough o easy and eliable ex apola ion o he ze o le el on o
he eac ed a ea, such ha no opog aphic g adien was supe imposed. (ii) In case o he
MSA, he si ua ion was ypically mo e di icul , because he polished 3 mm samples did
no ha e pe ec ly plane su aces bu we e a he ounded due o hei highe polishing
esis ance o py ho i e compa ed o he su ounding PMMA. The esul ing e o s in
de ini ion o he ze o le el we e minimized by applying a pa abolic la ening o he heigh
images, based on he masked egions (Fig. 4-2d). The esul ing sys ema ic e o s a e
es ima ed o be less han 1 µm based on he ypically obse ed polishing elie be o e
ea men . The unce ain y o he dissolu ion a es is ypically in he ange o 5×10-7 mol
Fe/m2s o less o e ching dep hs > 1 µm and s ems mainly om a ia ions o measu ed
high di e ences ac oss he eac ed su aces. In case o e ching dep hs < 1 µm ela i e
unce ain ies become la ge , due o la ge con ibu ion o e o s ela ed o he polishing
elie be o e eac ion.
4.4. Resul s
4.4.1. Gene al Obse a ions and Iden i ica ion o Al e a ion Phases
4.4.1.1. Expe imen s wi h FeCl3 Solu ion−Su ace Mine alogy
A e expe imen al ea men , exposed py ho i e su aces showed coa ings o a iable
hickness and composi ion. FeCl3 expe imen s a pH 1.8-2.0 esul ed in ei he hick (4-5
µm), yellowish c us s o e y hin (< 200 nm), i idescen coa ings, depending on he
sample and c ys allog aphic o ien a ion o he su ace (Fig. 4-2e). Raman spec oscopy
a es s he p esence o elemen al sul u in he hick c us s and powde XRD o sc aped
ma e ial indica es i o be o ho hombic α-sul u , indica ing an incomple e sul ide
oxida ion acco ding o eac ion 4-4. Low acuum SEM images show ew euhed al sul u
c ys al (1-10 µm) and dominan ly collo o m o sligh ly an-shaped agg ega es (Fig. 4-
118
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
4a,b). Unde lying py ho i e showed a ib ous o mesh-like ex u e (Fig. 4-4c). SEM in
si u imaging and TEM imaging o sc aped and FIB sec ioned c us s (Fig. 4-4d) shows ha
his ma e ial o ms a sponge-like ne wo k con aining dispe sed o clumped od-like Fe
oxyhyd oxide c ys als and abundan oids, which likely o igina ed om e apo a ed sul u ,
which is no s able in high acuum (Fig. 4-5a,b). The small (< 80 nm) od shaped c ys als
ha e been iden i ied as akaganei e by TEM-SAED (Fig. 4-5d). In addi ion, FIB-sec ions
o he c us s show b oad di ac ion ings ha a e consis en wi h poo ly c ys alline 2-line
(2L-) e ihyd i e (Fig. 4-5d,e).
FIGURE 4-4. SEM-SE images o py ho i e al e ed in FeCl3+HCl solu ion o ~650 hou s. (a)
Elemen al sul u c ys als and an-shaped agg ega es (low acuum SEM). (b) Collo o m agg e-
ga es o elemen al sul u (low acuum SEM). (c) Fib ous, mesh-like ex u e o py ho i e benea h
he al e a ion laye . (d) FIB c oss sec ion h ough he al e a ion laye showing a hickness o 4.5 o
5 µm. (e) EUL {110} su ace, on which no elemen al sul u o med. 4C-py ho i e lamellae we e
a acked s onge and show mo e in ense pi ing. The box ma ks he loca ion o an ex ac ed FIB
oil o TEM s udy. ( ) BF-TEM image o FIB sec ion ma ked in (e). 4C-py ho i e is s ongly
winned and shows la ge and deepe e ch pi s han adjacen NC-py ho i e.
TEM-EDX mappings o he sul ide in e ace egion (Fig. 4-5 ) e eal s ong
en ichmen o oxygen di ec ly (< 100 nm) a he in e ace. This oxygen is bound o a
dense laye o Fe oxide o oxyhyd oxide a ached o he sul ide and sul u shows an ab up
dec ease a he sul ide-oxide in e ace. We ound no e idence o sul u en ichmen a he
in e ace on scales o se e al ens o nm. Fil e esidues om he eac ion solu ion con ain
akaganei e c ys als iden ical o hose ound in he c us s, sugges ing ha akaganei e
p ecipi a ed om he solu ion and was apped in he o ming al e a ion c us s. 2L-
119
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
e ihyd i e and α-sul u likely o med in si u du ing oxida i e dissolu ion o he
py ho i e.
FIGURE 4-5. Analy ical TEM esul s o al e a ion phases on py ho i e eac ed in FeCl3+HCl
solu ion o ~650 hou s a 30 o 35 °C. Fo he con ex see Fig. 4-4c and d, which shows he c us s
be o e and du ing FIB p epa a ion. (a) BF-TEM. Sponge-like al e a ion laye composed o 2-line
e ihyd i e (2L-Fh) and akaganei e (Ak, od-like c ys als, a ows) on co oded py ho i e. Voids
we e likely illed by elemen al sul u , which e apo a ed in acuum. (b) BF-TEM. Al e a ion laye
on co oded 4C-py ho i e ( winned). A P laye has been deposi ed by FIB o p o ec he oxyhy-
d oxide c us om he ion beam. (c) BF-TEM. De ail o (b) showing he ough py ho i e-
oxyhyd oxide in e ace. (d) TEM-SAED pa e n ob ained om he oxyhyd oxide c us in (a).
Spo y di ac ion ings o akaganei e and di use di ac ion om 2-line e ihyd i e a e p esen .
(e) TEM-SAED pa e n om he al e a ion laye o a H2O2-H2SO4 expe imen a pH 2.90 o
compa ison. Akaganei e is absen he e and he wo b oad di ac ion ings o 2-line e ihyd i e
domina e. ( ) Scanning TEM da k- ield image (STEM-DF) and co esponding EDX X- ay ele-
men al dis ibu ion maps o he sul ide-oxyhyd oxide in e ace depic ed in (b) and (c). Oxygen is
clea ly en iched a he eac ion in e ace and sul u shows a sha p d op wi hou any e idence o
en ichmen .
4.4.1.2. Expe imen s wi h FeCl3 Solu ion−Py ho i e Reac i i y and Expe imen al
Rep oducibili y
In wo eplica e expe imen s (using wo di e en MSA: H03 and H05) we ound
e idence ha he 4C-dominan DAL sample eac ed s onge han EUL. The {hk0} aces
o DAL eac ed s onges and p oduced hick al e a ion c us s and elemen al sul u in bo h
expe imen s. The (001) aces eac ed leas , showing only e y hin Fe oxyhyd oxide
coa ings and no sul u . In case o EUL, mo e a ia ion was obse ed. Exposed {110} aces
showed s onges eac i i y, bu p oduced elemen al sul u only in one eplica e un
(H03_02), while in he o he un (H05_01) s ong and p e e ed pi ing o he 4C lamellae
was obse ed (Fig. 4-4e, ). {100} aces eac ed weakly in bo h uns and p oduced no
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
sul u . (001) aces eac ed weakly as well and p oduced no sul u , analogous o he DAL
sample.
The ailu e o ep oduce he EUL {110} esul s mos likely o igina ed om
he e ogenei ies in he a io 4C-/NC-py ho i e, which can be locally domina ed by 4C-
py ho i e, causing eac i i y simila o he 4C-dominan DAL sample. The EUL samples
o he H05 MSA we e con i med o con ain ully mixed 4C-/NC-py ho i e and
subsequen expe imen s in ol ing H2O2 we e conduc ed using his sample assembly.
De e mina ion o absolu e a es and eac i i y di e ences be ween 4C- and NC-py ho i e
in he FeCl3- uns aced se e al di icul ies: (i) Masking o he sul ide su aces was
gene ally no s able enough o he long un du a ion o one mon h and solu ion c ep
unde he supposedly p o ec i e ape, causing locally enhanced dissolu ion along he mask
edges. The cause o his beha io is p obably he local o ma ion o accumula ion o acid
o oxidan species due o poo exchange wi h he bulk solu ion. This appa en ly leads o
inc eased dissolu ion speeds in he a ec ed egions. (ii) A e one mon h o eac ion,
in en ionally exposed py ho i e su aces had ei he eac ed e y s ongly and we e oo
ough o esol e 4C and NC a eas o eac ed e y slowly wi h di e ences be ween 4C and
NC being oo small o eliable e alua ion (i.e., < 100 nm). Only in one ins ance, he non-
sul u -p oducing EUL {110} su ace o H05, showed much s onge pi ing o he 4C
lamellae compa ed o he NC ma ix, as no ed abo e.
4.4.1.3. Expe imen s wi h H2O2 Solu ion−Su ace Mine alogy
Expe imen s in ol ing H2O2 as oxidan we e quicke and p oduced soundly e aluable
esul s (Fig. 4-2 ,g). Simila ly o he FeCl3 expe imen s, hey showed µm- hick al e a ion
c us s composed o elemen al sul u , bu p oduced li le Fe oxyhyd oxides a compa able
pH. Also he e, he o ma ion o elemen al sul u indica es incomple e oxida ion o he
sul ide ( eac ion 4-7). A change in phase composi ion was obse ed o ake place a pH
2.65-2.70, abo e which elemen al sul u did no o m anymo e and p ecipi a ion o Fe
oxyhyd oxide s ongly inc eased (Fig. 4-2g). This change co esponds o an o e all
change in eac ion beha io o py ho i e as de ailed below. SAED pa e n and TEM-EDX
spec a show ha he Fe oxyhyd oxide o ming a highe pH is simila o 2L- e ihyd i e,
bu con ains app eciable amoun s o sul a e wi h a mola SO42-/Fe3+ a io o app ox. 0.22.
This composi ion is a he close o a sul a e- ich schwe manni e (Bigham e al. 1994).
Elemen al sul u is absen in hese c us s and a endency o s onge eac i i y on (001)
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
su p isingly s ong wi h a es la ge han 7×10-6 mol m-2s-1. Because he majo i y o {hk0}
aces o DAL and EUL eac ed e y slowly unde hese condi ions, we in e p e his
beha io as anomalous as ou lined in sec ion 4.4.3.4. None heless, he obse a ions a pH
2.88 o 2.92 demons a e ha he change in eac ion beha io a pH 2.70 is accompanied
by a change in he aniso opy o eac ion speeds. This is mos p ominen ly cha ac e ized
by a dec ease o eac i i y on {hk0} su aces by a ac o o 10 when he pH becomes
la ge han 2.70. Al hough a pH < 2.70 he (001) su aces a e he mos s able ones, hey
a e he leas s able ones a pH > 2.70. This beha io is consis en wi h mic os uc u al
obse a ions ob ained on he sul ide in e aces by SEM as de ailed in sec ion 4.4.4.
4.4.3.3. Con ol o Supe s uc u e on Dissolu ion Aniso opy
The supe s uc u es o py ho i e appea o in luence he di ec ion dependence o
dissolu ion only e y li le, because no signi ican di e ences be ween {100} and {110} in
4C- ich DAL py ho i e and among DAL and EUL py ho i e a e obse ed. Wi h espec o
he monoclinic 4C supe s uc u e, he p isma ic {hk0} planes (based on he hexagonal
subs uc u e) a e no longe symme y equi alen due o acancy o de ing and, hence,
{100} and {110} su aces migh eac sys ema ically di e en ly i he acancy
a angemen s ongly con ols he aniso opic beha io . Since no such sys ema ic
di e ences ha e been obse ed, he aniso opic beha io appea s o depend p ima ily on
he hexagonal NiAs- ype subs uc u e. Occasionally he s ong winning in EUL 4C-
py ho i e becomes appa en on e ched su aces by sligh eac i i y di e ences be ween
he indi idual win domains (Fig. 4-6b). This can be a ibu ed o weak eac ion aniso opy
wi h espec o he 4C supe s uc u e, because he winning a ises solely om he o de ing
o acancies and o a ion o he o de ing scheme by 60 o 120° abou he c axis, which
would be a symme y ope a ion wi h espec o he basic hexagonal NiAs- ype c ys al
s uc u e. Howe e , his e ec is oo small o be quan i ied.
4.4.3.4. Anomalous Dissolu ion Beha io in Mic oen i onmen s
To es o o ien a ion dependence, he same sample assembly was used in all MSA
uns and all indi idual samples wi hin he assembly had been polished simul aneously o
iden ical su ace inishes jus p io o he uns. Hence, we exclude g ossly di e ing
s a ing condi ions, such as sample miso ien a ion o su ace oughness as cause o he
obse ed anomalous beha io o DAL {100} and {110} su aces (Fig. 4-8b). As ou lined
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
abo e (sec ion 4.4.1.3.), he expe imen s abo e pH 2.70 showed s ong de elopmen o Fe
oxyhyd oxide c us s and gene ally we obse ed ha unde hese condi ions also s ong
de e io a ion o he masks occu ed om solu ion c eeping and eac ing unde he
p o ec i e ape (Fig. 4-2d,g). Owing o he hick oxyhyd oxide c us s, his led in many
ins ances o he o ma ion o deep enches along he mask edges due o localized
o ma ion o accumula ion o acid o oxidan species. We hink ha he wo cases o
anomalous dissolu ion esul ed om such eac i e mic oen i onmen s, which caused
p e e ed la e al dissolu ion s a ing om he enches. Conside ing (001) being he mos
eac i e su aces unde hese condi ions, his la e al dissolu ion could ha e easily ou paced
he dissolu ion no mal o he {hk0} aces unde a o able condi ions when he
oxyhyd oxide c us did no allow exchange wi h he bulk solu ion o he expe imen . The
eac i e mic oen i onmen c ea ed in his way did no induce a e e sal o he eac ion
mechanism obse ed a pH < 2.70, because also in case o he anomalous beha io we did
no de ec he o ma ion o elemen al sul u . Likely he d i ing mechanism in his case was
an inc ease in concen a ion o oxidan (dissol ed Fe3+, eac i e oxygen species, o bo h).
This beha io demons a es ha he eac ion in e ace egion, comp ising he sul ide
in e ace and he adjacen laye o seconda y phases, is a complex, dynamical sys em ha
can unde go ab up changes as consequence o small dis u bances.
4.4.4. In e ace Mo phology
The pH dependen changes in eac ion beha io also mani es hemsel es in he mic o-
scale mo phology o he sul ide eac ion in e aces (Fig. 4-9). A e emo al o he
al e a ion laye s, SEM seconda y elec on imaging o he SSA EUL {110} expe imen al
se ies shows ha a he eac i i y maximum be ween pH 2.3 and 2.7 he in e aces
de eloped e y ough and scaly mo phologies (Fig. 4-9a,b,c). The py ho i e scales a e
domina ed by (001) aces, ha e hicknesses in he o de o ens o hund eds o nm, and
p o ude e ically ou o he {110} plane. This indica es educed eac i i y on he (001)
aces and p e e ed dissolu ion along he clea age planes in he di ec ions pe pendicula o
[001]. The esul ing su ace ex u es a e e y simila o he saw oo h pa e ns ound in
a i icially and na u ally ( e es ial and ma ian) wea he ed py ho i e (e.g., C uz e al.
2005; Che ie e al. 2011). Images o expe imen s conduc ed a pH 2.03 and 2.22, i.e.,
below he eac i i y maximum, show ha he de elopmen o py ho i e scales somewha
dec eases, bu dissolu ion s ill p oceeds p e e ably pe pendicula o [001].
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
A highe pH, close o he ansi ion poin a pH 2.70, he su ace ex u es we e ound
o become smoo h, indica ing inc easingly p e e ed dissolu ion on (001) aces. Based on
images showing ough 4C su aces nex o smoo h NC su aces a pH 2.58 (Fig. 4-9b), he
expe imen s sugges ha he change in aniso opic beha io occu s a sligh ly lowe pH
o he NC phase compa ed o he 4C phase. A pH 2.66 (Fig. 4-9d, ) we ound mos ly
smoo h su ace ex u es o bo h 4C- and NC-py ho i e, while he NC phase s ill eac ed
sligh ly as e han he 4C phase. Some 4C a eas in his expe imen showed he ough,
scaly ex u e ypical o lowe pH, sugges ing ha acid p oduc ion migh ha e locally
dec eased he pH. Beyond he ansi ion poin smoo h ex u es de eloped on all py ho i e
su aces, albei dissolu ion p oceeded a s ongly educed a es (Fig. 4-9e). Locally
inc eased pi ing could be obse ed in some cases.
FIGURE 4-9. SEM-SE images o cleaned py ho i e eac ion in e aces o H2O2-H2SO4 expe i-
men s a 35 °C. A pH dependen end in in e ace ex u es is appa en , mimicking he changes in
eac ion aniso opy. (a) pH 2.41 (13 h). Bo h 4C- and NC-py ho i e a e ough wi h s ong de el-
opmen o a scaly ex u e domina ed by (001) su aces. (b) pH 2.58 (13 h). 4C-py ho i e s ill
shows a ough and scaly ex u e, bu NC-py ho i e has become smoo h, indica ing a change o
he eac ion mechanism a sligh ly lowe pH. (c) pH 2.58 (13 h). De ail o he scaly 4C-py ho i e
su ace in (b). Indi idual scales ha e hicknesses o 10s o 100s o nm. (d) pH 2.66 (13 h). Close
o pH 2.70 bo h 4C- and NC-py ho i e de elop smoo h in e aces. NC-py ho i e s ill eac s
sligh ly as e han 4C-py ho i e (app ox. 15 %). (e) pH 2.90 (44 h). The sul ide in e aces a e
e y smoo h, 4C-py ho i e eac s as e han NC-py ho i e a s ongly educed o e all a es. ( )
pH 2.66 (13 h). De ail o he smoo h 4C-py ho i e su ace in (d). Scale and o ien a ion a e he
same as in (c).
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
4.4.5. HR-TEM In e ace Obse a ions
F om wo expe imen al uns we ob ained FIB-p epa ed oils sui able o high-
esolu ion (HR) TEM s udy o he eac ion in e ace in o de o sea ch o e idence o
incomple e dissolu ion and/o he o ma ion o S-en iched sul ides (Fig. 4-10). The DAL
{100} su ace eac ed a pH 1.95-1.99 o 647.8 h in 0.01 mol/L FeCl3 solu ion showed
benea h he sponge-like 2L- e ihyd i e c us a sha p ansi ion owa d p is ine 4C-
py ho i e, which supe s uc u e could be de ec ed less han 15 nm om he sul ide/oxide
in e ace by as Fou ie ans o ma ion (FFT) o he HR image (Fig. 4-10a). Wi hin he
~15 nm in e al be ween 4C-py ho i e and he in e ace, FFT shows no supe s uc u e
pe iodici y bu clea ly a es s he p esence o he NiAs based undamen al s uc u e o
py ho i e. This indica es ha no c ys allog aphically dis inc o amo phous phase o med
a he in e ace and he su ace laye a he consis s o a diso de ed py ho i e. Su eys by
TEM-EDX on his oil did no indica e he p esence o ma casi e (FeS2), which is
analy ically esol able om py ho i e by TEM-EDX and could be expec ed o o m,
based on known opo ac ic ela ionships wi h py ho i e (Flee 1978). Also he de ec i e
e agonal Fe2S3 phases p oposed by Jones e al. (1992) should ha e been esol able i
occu ing on nm-scales. In he oil aken om he DAL (001) su ace (MSA H05) eac ed
a pH 2.86-2.93 o 44.3 h in 0.1 mol/L H2O2 we ound well o de ed 4C-py ho i e less
han 5 nm om he sul ide/oxide in e ace (Fig. 4-10b). FFT sugges s he p esence o a
py ho i e supe s uc u e e en close o he in e ace, bu his may due o delocaliza ion in
HR imaging. These obse a ions, as well as su eys o se e al o he FIB sec ions, which
un o una ely we e oo hick o HR-TEM s udy, bu showed no p esence o FeS2 based on
TEM-EDX, sugges ha he oxida i e dissolu ion o py ho i e unde he condi ions
s udied is, wi h he excep ion o sul u p ecipi a ion, mos ly comple e and may p oceed
wi h he o ma ion o acancy-diso de ed py ho i e in some cases.
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
FIGURE 4-10. High esolu ion TEM images o he sul ide-oxyhyd oxide in e ace. Fo ma ked
squa es Fas -Fou ie -T ans o ms (FFT) a e shown, accompanied by he bulk SAED pa e ns. (a)
DAL {100} su ace eac ed in FeCl3+HCl solu ion a 35 °C o 648 hou s a pH 1.95−1.99 (de ail
o in e ace shown in Fig. 4-5c). 4C-py ho i e wi h clea ly iden i iable supe s uc u e pe iodici y
(a ows in FFT pa e n) is p esen less han 15 nm om he sul ide-oxyhyd oxide in e ace. Close
o he in e ace, he NiAs- ype subs uc u e o py ho i e can be de ec ed, bu supe s uc u es a e
no de ec able. (b) DAL (001) su ace eac ed in H2O2+H2SO4 solu ion a 35 °C o 44.3 hou s a
pH 2.90. Supe s uc u e pe iodici y o 4C-py ho i e (a ows) is de ec able di ec ly a and below
he sul ide-oxyhyd oxide in e ace.
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
4.5. Discussion
4.5.1. pH Dependence o Dissolu ion Ra es and Aniso opy
4.5.1.1. Dissolu ion Ra es and he Isoelec ic Poin
Ou expe imen al esul s show wo e ec s aking place as he pH o he H2O2 solu ion
changes. The i s e ec is he change in aniso opy o a es o dissolu ion, leading o an
inc ease o eac ion speed on (001) su aces and dec ease o speed on {hk0} su aces as
pH inc eases beyond he ansi ion poin a pH 2.70. The second e ec is he change in
ela i e eac ion a es be ween 4C- and NC-py ho i e a his c i ical pH. The change in
ela i e eac ion a es is a second-o de e ec due o di e en deg ees o absolu e
eac i i y change o 4C and NC imposed a he c i ical pH: On {hk0} su aces a pH 2.70
he d op in absolu e a es o NC-py ho i e is la ge han ha o 4C-py ho i e, leading o
e e sal o he ela i e a es.
The sha p d op in absolu e eac ion a es close o he ansi ion poin a pH 2.70 is
associa ed wi h a change in he eac ion mechanism as he p oduc ion o elemen al sul u
ceases. In p inciple, he obse ed changes in eac ion beha io could be due o a change in
he oxidan ’s specia ion. Howe e , H2O2 is a weak acid wi h a pKa o app ox. 11.4 a 35
°C (Pe in 1969) and, hence, he e a e no dep o ona ion eac ions expec ed in he low pH
ange o ou expe imen s. This leads us o in e ha he obse ed beha io is p ima ily
con olled by in insic p ope ies o he py ho i e- luid in e ace and no by he specia ion
o he bulk solu ion. The ansi ion poin a pH 2.70 app oxima ely coincides wi h he
isoelec ic poin (IEP) o syn he ic py ho i e de e mined by Dekke s and Schoonen (1994)
o occu be ween pH 2.0 and 2.5. La e wo k on na u al py ho i e showed ha he IEP
may lie close o 3.0-3.3 (Bebie e al. 1998). A pH below he IEP, he ze a po en ial o he
py ho i e- luid in e ace is posi i e and u ns s eeply nega i e abo e he IEP. Because he
abo e s udies de e mined bulk IEPs based on elec opho esis o inely dispe sed
py ho i e, di e ences o ac ual IEPs o plane, single c ys al su aces could be expec ed
due o aniso opy. Acco ding o he in e p e a ion o Dekke s and Schoonen (1994),
changing su ace cha ges a e p ima ily linked o he specia ion o hiol(sic)/sul hyd yl
g oups (≡S−H0) on he py ho i e su ace, which esul om he hyd olysis o
uncoo dina ed sul u a oms. These g oups migh be neu al, p o ona ed (≡S−H2+) o
dep o ona ed (≡S−−) depending on pH. Me al hyd oxide g oups (≡Fe−OH) a e expec ed o
con ibu e li le o he su ace specia ion when ac i i ies o dissol ed e ous i on and
sul ide a e low. Inc eased Fe2+ ac i i ies ela i e o sul ide will inc ease he p opo ion o
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
Fe hyd oxide su ace g oups and migh lead o addi ional cha ge e e sals a highe pH,
bu he i s cha ge e e sal/IEP a lowes pH is li le a ec ed. Hence, in ou expe imen s
he sul u su ace specia ion appea s o be an impo an con olling ac o on dissolu ion
a es. Howe e , as de ailed below, sul hyd yl g oups may no necessa ily be he p ominen
eac i e cen e s on he su aces, a leas a low pH < 2.70.
4.5.1.2. Dissolu ion Aniso opy and Chemical S a e o Py ho i e Su aces
The di e en eac ion beha io o dis inc c ys al su aces obse ed in ou expe imen s
indica es ha he a ailabili y o su ace g oups is in insically con olled by he c ys al’s
aniso opy. Despi e s ong nm- o µm-scale oughness de elops du ing he dissolu ion, he
aniso opy s ill s a is ically de e mines he con ibu ions o su ace species in ol ed a he
eac ion in e ace. Becke e al. (1997) p esen ed STM and o he expe imen al e idence as
well as quan um mechanical calcula ions sugges ing ha py ho i e (001) su aces a e
e mina ed by sul u a oms in acuum. Th ough eac ion wi h gaseous oxygen hey
obse ed s onges oxida ion nea he co ne s o (001) su ace e aces, whe e Fe a oms
a e mo e eadily a ailable compa ed o he S domina ed e ace planes. Acco dingly, hey
sugges ha he su ace oxida ion ia he ini ial o ma ion o Fe(III) oxyhyd oxides is
hinde ed by he small numbe o Fe a oms exposed on he (001) su aces. I his si ua ion
applies o py ho i e in aqueous media as well, he slow dissolu ion on (001) su aces a
low pH can be in e p e ed in e ms o dec eased a ailabili y o i on ela i e o he {hk0}
su aces, on which Fe laye s a e exposed, and ≡Fe−OH g oups eadily o m. These g oups
a e likely he p ime eac i e cen e s ha a e in ol ed in he oxida ion o Fe(III)
oxyhyd oxides and dissol ed Fe3+. Reasons o quicke Fe oxida ion by O2 ela i e o
sul u may lie in he easie ans e o spin o he elec onic sys em o i on as discussed by
Becke e al. (1997). Compa ed o Fe, oxida ion o S equi es ela i ely high ac i a ion
ene gy, because O2 in his case has o change i s spin s a e om iple o single (high o
low spin). The p e e ed oxida ion o Fe in ou expe imen s is clea ly indica ed by he
o ma ion o elemen al sul u a pH < 2.70. The documen ed o ma ion o polysul ide in
XPS in es iga ions on py ho i e oxida ion (e.g., Buckley and Wood 1985ab; Jones e al.
1992; P a e al. 1994) is consis en wi h such a ou e as polyme ized sul u chains would
e en ually me ge in o S8 ings o elemen al sul u h ough u he oxida ion (Wang 2007).
Inc eased eac i i y o he (001) su aces abo e pH 2.70 and he concomi an
disappea ance o elemen al sul u as eac ion p oduc s ongly poin s o a change in he
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
eac ion mechanism. Assuming dominan sul u e mina ion on (001) su aces, he
obse a ions a e consis en wi h a mechanism ha a acks p e e en ially a sul u si es and
in ol es apid and comple e sul ide o sul a e oxida ion.
4.5.1.3. Oxidan Species
The oxidan species in expe imen s in ol ing H2O2 a e impo an o he unde s anding
o he dissolu ion p ocess. T iple O2 and H2O2 hemsel es a e likely he leas eac i e
species ( he la e due o i s ela i ely s able O-O bond), bu dissocia ion o H2O2 migh
yield a ange o o he eac i e oxygen species (ROS) capable o oxidizing he py ho i e
su aces. Besides single O2, adical species such as supe oxide (·O2−) and hyd oxyl (·OH)
adicals a e candida es o ROS. Pa icula ly he hyd oxyl adical can o m in Fen on- ype
eac ions in he p esence o Fe2+ (e.g., Aus e al. 1985; Koppenol 1993; Hug and Leupin
2003). Nei he he H2O2/ROS sys em, no he specia ion o i on (i.e., Fe3+ s. Fe[OH]2+) is
expec ed o show a compa ably sha p change a ound pH 2.70 as obse ed in ou
expe imen s. Li e al. (2010) showed ha py ho i e Fen on eac ions p obably can occu
a he mine al luid in e ace due o elease o Fe2+ om he sul ide. Hug and Leupin
(2003) demons a ed h ough use o 2-p opanol as adical sca enge (p oducing ace one)
ha he p oduc ion o adical species in Fen on- ype eac ions is g adually inc easing as
pH is lowe ed o pH 3. The addi ion o 0.7 mol/L 2-p opanol (i.e., he se en old
concen a ion o he oxidan H2O2) did no change he dissolu ion beha io in ou
expe imen – i is, howe e , unclea whe he he a ailabili y o he adical sca enge 2-
p opanol a he eac ion on was sui able and he eac ion kine ics o ace one o ma ion
capable o in e e ing wi h he p oduc ion and eac ion o adical ROS a he sul ide
in e ace. Addi ion o up o 0.1 mol/L FeSO4 as p omo e o Fen on- ype eac ions did no
p oduce signi ican di e ences, excep ha he p ecipi a ion o elemen al sul u was
s ongly inhibi ed. The H2O2- ee con ol expe imen using Fe2(SO4)3 as sole oxidan
(excep a mosphe ic O2) yielded eac ion a es and diminished sul u p oduc ion simila ly
o he FeSO4+H2O2 expe imen s. In his ega d, i mus be easoned ha dissol ed Fe3+,
o med by he eac ion o added Fe2+ and H2O2, was a he he con olling ac o han he
adical ROS o med in he solu ion. E en ually he ac ion o adical ROS can no be
excluded conclusi ely, bu hei e ec seems no o be conside ably s ong compa ed o
Fe3+ as oxidan o py ho i e.
Based on esul s o Dekke s and Schoonen (1994) and Bebie e al. (1998) he py ho i e
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CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
su aces a pH < IEP a e likely domina ed by posi i ely cha ged S e n laye s o p o ona ed
sul hyd yl g oups. This iew implies ha he oxidan species ele an o he oxida ion o
Fe si es migh ca y nega i e cha ge, causing epulsi e Coulomb in e ac ions and g ea ly
educed eac ion a es a pH > IEP, when sul hyd yl g oups a e dep o ona ed. A candida e
o his species may be he supe oxide ion (·O2−) o ming h ough Fen on- ype eac ions in
he Fe- ich in e ace egion. A pH > IEP, he e e sed ze a po en ial migh allow o he , ye
elusi e, oxidan species o a ack he sul u domina ed (001) aces.
4.5.1.4. Non-oxida i e Dissolu ion and he Role o Fe3+
An al e na i e explana ion o he s ong change in dissolu ion beha io a he IEP
migh be a undamen al swi ch be ween he con ibu ion o oxida i e and non-oxida i e
dissolu ion. Thomas e al. (1998) showed ha non-oxida i e dissolu ion o py ho i e is
abou 1000 imes as e han oxida i e dissolu ion and, hence, a pH < IEP inc eased
con ibu ion o non-oxida i e dissolu ion migh explain s ongly enhanced eac ion a es.
Howe e , he abundan p ecipi a ion o elemen al sul u a gues agains non-oxida i e
dissolu ion, which would a he p oduce dissol ed sul ide species. Mo eo e , expe imen s
by Janzen e al. (2000) indica e a ac o 10 as e py ho i e dissolu ion in ae a ed
hyd ochlo ic acid a pH 2.75 compa ed o he analogous expe imen unde oxygen- ee
condi ions, indica ing ha non-oxida i e dissolu ion is no necessa ily as e .
The non- o ma ion o signi ican amoun s o elemen al sul u when py ho i e is
exposed o FeSO4+H2O2 and Fe2(SO4)3 media indica es ha he oxida ion owa d sul a e
ad ances o mo e comple eness unde condi ions when signi ican Fe3+ is p esen . Also
ou MSA expe imen s using FeCl3 showed ha , aside om o ien a ion dependence, DAL
py ho i e p ecipi a e abundan sul u while EUL p ecipi a ed li le o none. The eason o
his beha io is unclea . Va ia ions in he con ibu ion o oxida i e e sus non-oxida i e
dissolu ion, which may depend on he s uc u e ype o o he ac o s such as ace elemen
o oxygen con en s wi hin he py ho i e, migh a ec he p ecipi a ion o sul u .
4.5.2. Reac i i y Di e ences be ween 4C- and NC-Py ho i e
Signi ican di e ences be ween 4C- and NC-py ho i e a e clea ly e iden in ou H2O2
dissolu ion expe imen s. As ou lined abo e, he change in eac i i y o NC-py ho i e
ela i e o 4C-py ho i e is due o a di e en deg ee o change in indi idual, absolu e
dissolu ion a es a he ansi ion poin close o pH 2.70. The 50 o 80 % eac i i y
136
CHAPTER 4 OXIDATIVE DISSOLUTION OF PYRRHOTITE
di e ence o NC-py ho i e ela i e o 4C-py ho i e is qui e ou s anding, conside ing ha
bo h phases a e ex emely simila in composi ion wi h a jus 2.4 % highe Fe/S a io in
NC-py ho i e. Al hough he e is e idence ha Fe a ailabili y on he su aces is a
con olling ac o o oxida i e dissolu ion a es, he e mus be o he ac o s o explain he
la ge e ec o mino a ia ion in he Fe/S a ios. Gi en iden ical basic s uc u es, his
ac o mus be he na u e o he acancy supe s uc u es. The mos s iking di e ence
be ween he 4C and NC supe s uc u es is he p esence o double illed Fe laye s in he
idealized NC s uc u e as shown in Figu e 4-1c and p e ious wo k (Ha ies e al. 2011).
Unlike 4C-py ho i e, which has no double illed Fe laye s, NC-py ho i e wi h an N alue
o 4.8 o 4.85 (as applicable o ou EUL sample) is expec ed o ha e abou 35 % o i s Fe
subla ice cons i u ed by double illed laye s (Fig. 4-11a). Because his igu e, in con as
o he ela i e Fe/S a ios, is compa able o he magni ude o obse ed eac i i y
di e ences, we sugges ha he su ace exp ession o his di e ence in bulk s uc u e is a
signi ican ac o o he dis inc a es o oxida i e dissolu ion o NC- and 4C-py ho i es.
The FeCl3 MSA expe imen s showed ha 4C-py ho i e has a endency o eac as e han
NC-py ho i e e en a pH as low as 1.8 o 1.9 in p esence o signi ican concen a ions o
dissol ed Fe3+. This indica es ha he dis inc su ace eac ion mechanisms ope a e in case
o Fe3+ o ROS as oxidan s.
Un o una ely, he e is li le possibili y o making ad hoc in e ences abou he ac ual
su ace e mina ion o complex py ho i e supe s uc u es on {hk0}su aces. XPS s udies
by Nesbi e al. (2001) indica e ha esh py ho i e su aces ha bo monome ic S2−
su ace species and show no clea e idence o dime iza ion o sul u . This may poin o
a he li le su ace econs uc ion. Hence, one p ominen bulk-s uc u al ea u e ha migh
con ibu e o su ace eac i i y is he p esence o ace-sha ing Fe-S coo dina ion
oc ahed a, which occu in chains pa allel o he [001] s acking di ec ion. The a he
unusual ace-sha ing o Fe polyhed a wi h sho Fe-Fe dis ances o abou 0.289 nm (de
Villie s e al. 2009) leads o ela i ely s ong elec onic in e ac ions among he chain
a oms. Fe-Fe sepa a ion o less han 0.3 nm is expec ed o esul in o e lapping o Fe 3d
2g o bi als and c ea ion o π-bonded c ys al o bi als along he [001] di ec ion in
s oichiome ic FeS, which s ongly enhance elec onic anspo p ope ies in his di ec ion
(Goodenough 1962; Wang and Sal eson 2005). Due o acancies wi hin he Fe laye s
hese chains a e unca ed in non-s oichiome ic py ho i e, esul ing in a leng h o 7 Fe
a oms in case o 4C-py ho i e (Fig. 4-11b). Addi ion o double illed Fe laye s (o mo e
137
BIBLIOGRAPHY
Dekke s M.J. and Schoonen M.A.A. (1994) An elec okine ic s udy o syn he ic g eigi e and py -
ho i e. Geochimica e Cosmochimica Ac a 58, 4147−4153.
Desbo ough G.A. and Ca pen e R.H. (1965) Phase ela ions o py ho i e. Economic Geology 60,
1431–1450.
Dódony I. (1997) Theo e ical de i a ion and iden i ica ion o possible wo-laye liza di e
poly ypes. In Modula Aspec s in Mine alogy, EMU No es in Mine alogy 1, 57–80 (ed. S.
Me lino). Eö ös Uni e si y P ess, Budapes , 449 p.
Dódony I. and Pós ai M. (1990) Py ho i e supe s uc u es; Pa II, A TEM s udy o 4C and 5C
s uc u es. Eu opean Jou nal o Mine alogy 2, 529–535.
D i s V. (1987) Elec on di ac ion and high- esolu ion elec on mic oscopy o mine al s uc u es.
Sp inge -Ve lag, Be lin, 304 p.
Eggle D.H. and Lo and J.P. (1993) Man le sul ide geoba ome y. Geochimica e Cosmochimica
Ac a 57, 2213–2222.
Ekmekçi Z., Becke M., Tekes E.B. and B adshaw D. (2010) The ela ionship be ween he
elec ochemical, mine alogical and lo a ion cha ac e is ics o py ho i e samples om di e en
Ni O es. Jou nal o Elec oanaly ical Chemis y 647, 133–143.
Ellio A.D. (2010) S uc u e o py ho i e 5C (Fe9S10). Ac a C ys allog aphica B 66, 271–279.
E schmann B., P ing A., Pu nis A., G gu ic B.A. and S ude A. (2004) A kine ic s udy o he
exsolu ion o pen landi e (Ni,Fe)9S8 om he monosul ide solid solu ion (Fe,Ni)S. Ame ican
Mine alogis 89, 39–50.
Flee M.E. (1978) The py ho i e-ma casi e ans o ma ion. Canadian Mine alogis 16, 31−35.
Flee M.E. (2006) Phase equilib ia a high empe a u es. In Sul ide Mine alogy and Geochemis y,
Re iews in Mine alogy and Geochemis y 61, 365–405 (ed. D.J. Vaughan). Mine alogical
Socie y o Ame ica, Chan illy, 714 p.
Flee M.E. and Pan Y. (1994) F ac ional c ys alliza ion o anhyd ous sul ide liquid in he sys em
Fe-Ni-Cu-S, wi h applica ion o magma ic sul ide deposi s. Geochimica e Cosmochimica Ac a
58, 3369–3377.
F ancis C.A., Flee M.E., Mis a K. and C aig J.R. (1976) O ien a ion o exsol ed pen landi e in
na u al and syn he ic nickeli e ous py ho i e. Ame ican Mine alogis 61, 913–920.
F oese E. and Gun e A.E. (1976) A no e on he py ho i e-sul u apo equilib ium. Economic
Geology 71, 1589–1594.
F os B.R. (1991) In oduc ion o oxygen ugaci y and i s pe ologic impo ance. Re iews in
Mine alogy and Geochemis y 25, 1–9.
Fuchs L.H., Olsen E. and Jensen K.J. (1973) Mine alogy, mine al-chemis y, and composi ion o
he Mu chison (C2) me eo i e. Smi hsonian Con ibu ions o he Ea h Sciences 10, 1-39.
Fue s enau M.C., Jameson, G. and Yoon R.-H. (2007) F o h lo a ion: a cen u y o inno a ion.
Socie y o Mining, Me allu gy, and Explo a ion, Li le on (USA), 897 p.
Fujiwa a K. (1957) On he pe iod o ou -o -s ep o o de ed alloys wi h an i-phase domain
s uc u e. Jou nal o he Physical Socie y o Japan 12, 7–13.
Geige T. and Bischo A. (1995) Fo ma ion o opaque mien als in CK chond i es. Plane a y and
Space Science 43, 486–498.
Geo gopoulou Z.J., Fy as K., So o H. and E angelou B. (1996) Feasibili y and cos o c ea ing an
i on-phospha e coa ing on py ho i e o p e en oxida ion. En i onmen al Geology 28, 61−69.
Gilde S.A., Egli R., Hochlei ne R., Roud S.C., Volk M.W.R., Le Go M. and de Wi M. (2011)
Ana omy o a p essu e-induced, e omagne ic o pa amagne ic ansi ion in py ho i e:
Implica ions o he o ma ion p essu e o diamonds. Jou nal o Geophysical Resea ch 116,
B10101.
Goodenough J.B. (1962) Ca ion-ca ion h ee-membe ed ing o ma ion. Jou nal o Applied Phys-
ics 33, 1197−1199.
144

BIBLIOGRAPHY
G ay N.F. (1997) En i onmen al impac and emedia ion o acid mine d ainage: a managemen
p oblem. En i onmen al Geology 30, 62–71.
G ay N.F. and Delaney E. (2010) Measu ing cummuni y esponse o ben ic mac oin e eb a es in
an e osional i e impac ed by acid mine d ainage by use o a simple model. Ecological
Indica o s 10, 668–675.
G øn old F. and S ølen S. (1992) The modynamics o i on sul ides II. Hea capaci y and
he modynamic p ope ies o FeS and o Fe0. 875S a empe a u es om 298.15 K o 1000 K, o
Fe0. 98S om 298.15 K o 800 K, and o Fe0. 89S om 298.15 K o abou 650 K.
The modynamics o o ma iona. The Jou nal o Chemical The modynamics 24, 913–936.
Guinie A., Bokij G.B., Boll-Do nbe ge K., Cowley J.M., Du o ic S., Jagodzinski H., K ishna P.,
de Wol P.M., Z yagin B.B., Cox D.E., Goodman P., Hahn Th., Kuchi su K. and Ab ahams
S.C. (1984) Nomencla u e o poly ype s uc u es. Repo o he In e na ional Union o
C ys allog aphy ad hoc Commi ee on he Nomencla u e o Diso de ed, Modula ed and
Poly ype S uc u es. Ac a C ys allog aphica Sec ion A 40, 399–404.
Gunsinge M.R., P acek C.J., Blowes D.W. and Jambo J.L. (2006) E alua ion o long- e m sul-
ide oxida ion p ocesses wi hin py ho i e- ich ailings, Lynn Lake, Mani oba. Jou nal o Con-
aminan Hyd ology 83, 149−170.
Guo W. and Eile J.M. (2007) Tempe a u es o aqueous al e a ion and e idence o me hane
gene a ion on he pa en bodies o he CM chond i es. Geochimica e Cosmochimica Ac a 71,
5565–5575.
Guymon M. (1991) S abilisa ion by en opy o incommensu a e long-pe iod o de ed alloys. Phase
T ansi ions 31, 107–115.
Guymon M., Po ie R. and G a ias D. (1980) E ude des phases o données à longue pé iode
i a ionnelle. Les alliages AuCu II e AuCu-Zn. Ac a C ys allog aphica Sec ion A 36, 792–795.
Hall A.J. (1986) Py i e-py ho ine edox eac ions in na u e. Mine alogical Magazine 50, 223–229.
Hallbe g K.B. (2010) New pe spec i es in acid mine d ainage mic obiology. Hyd ome allu gy 104,
448–453.
Hanowski N.P. and B ea ley A.J. (2001) Aqueous al e a ion o chond ules in he CM ca bonaceous
chond i e, Allan Hills 81002: implica ions o pa en body al e a ion. Geochimica e
Cosmochimica Ac a 65, 495–518.
Ha ies D., Pollok K. and Langenho s F. (2011) T ansla ion in e ace modula ion in NC-
py ho i es: Di ec imaging by TEM and a model owa d unde s anding pa ially diso de ed
s uc u al s a es. Ame ican Mine alogis 96, 716−731.
Hawley J.E. and Haw V.A. (1957) In e g ow hs o pen landi e and py ho i e. Economic Geology
52, 132–139.
Heaney P.J., Vicenzi E.P., Giannuzzi L.A. and Li i K.J.T. (2001) Focused ion beam milling: a
me hod o si e-speci ic sample ex ac ion o mic oanalysis o Ea h and plane a y ma e ials.
Ame ican Mine alogis 86, 1094–1099.
He zig P.M. and Hanning on M.D. (1995) Polyme allic massi e sul ides a he mode n sea loo : a
e iew. O e Geology Re iews 10, 95–115.
Ho ng C.-S. and Robe s A.P. (2006) Au higenic o de i al o igin o py ho i e in sedimen s?:
Resol ing a paleomagne ic conund um. Ea h and Plane a y Science Le e s 241, 750–762.
Hudson-Edwa ds K.A., Jamieson H.E. and Lo e mose B.G. (2011) Mine was es: pas , p esen ,
u u e. Elemen s 7, 375–380.
Hug S.J. and Leupin O. (2003) I on-ca alyzed oxida ion o a senic (III) by oxygen and by hyd o-
gen pe oxide: pH-dependen o ma ion o oxidan s in he Fen on eac ion. En i onmen al Sci-
ence and Technology 37, 2734−2742.
Huss G.R., Rubin A.E. and G ossman J.N. (2006) The mal me amo phism in chond i es. In
Me eo i es and he Ea ly Sola Sys em II, 567–586 (eds. D.S. Lau e a and H.Y. McSween J .).
145
BIBLIOGRAPHY
Uni e si y o A izona P ess, Tucson, 942 p.
Ikeda Y. (1992) An o e iew o he esea ch conso ium, “An a c ic ca bonaceous chond i es wi h
CI a ini ies, Yama o-86720, Yama o-82162, and Belgica-7904”. P oceedings o he NIPR
Symposium on An a c ic Me eo i es 5, 49–73.
Imlay J.A. (2003) Pa hways o oxida i e damage. Annual Re iews o Mic obiology 57, 395−418.
IUC (In e na ional Union o C ys allog aphy) (1992) Repo o he Execu i e Commi ee o
1991. Ac a C ys allog aphica A48, 922–946.
Izaola Z., Gonzalez S., Elco o L., Pe ez-Ma o J.M., Mada iaga G. and Ga cia A. (2007) Re ision
o py ho i e s uc u es wi hin a common supe space model. Ac a C ys allog aphica B 63, 693–
702.
Jambo J.L., Blowes D.W. and Ri chie I.M. (eds.) (2003) En i onmen al aspec s o mine was es.
Sho Cou se Handbook Vol. 31. Mine alogical Associa ion o Canada, O awa, 430 p.
Jamieson H.E. (2011) Geochemis y and mine alogy o solid mine was e: essen ial knowledge o
p edic ing en i onmen al impac . Elemen s 7, 381–386.
Janzen M.P., Nicholson R.V. and Scha e J.M. (2000) Py ho i e eac ion kine ics: Reac ion a es
o oxida ion by oxygen, e ic i on, and o nonoxida i e dissolu ion. Geochimica e Cosmo-
chimica Ac a 64, 1511−1522.
Jehanno G. and Pe io P. (1964) É ude adioc is allog aphique de AuCu II su monoc is aux.
Jou nal de Physique F ance 25, 966–974.
Jennings S.R., Dollhop D.J. and Inskeep W.P. (2000) Acid p oduc ion om sul ide mine als us-
ing hyd ogen pe oxide wea he ing. Applied Geochemis y 15, 235−243.
Johnson C.A. and P inz M. (1993) Ca bona e composi ions in CM and CI chond i es and
implica ions o aqueous al e a ion. Geochimica e Cosmochimica Ac a 57, 2843–2852.
Johnson D.B. and Hallbe g K.B. (2003) The mic obiology o acidic mine wa e s. Resea ch in
Mic obiology 154, 466–473.
Johnson D.B. and Hallbe g K.B. (2005) Acid mine d ainage emedia ion op ions: a e iew. Science
o he To al En i onmen 338, 3–14.
Jones C.F., LeCoun S., Sma R.S.C. and Whi e T.J. (1992) Composo ional and s uc u al al e a-
ion o py ho i e su aces in solu ion: XPS and XRD s udies. Applied Su ace Science 55,
65−85.
Kalinkin A.M., Fo sling W., Maka o D.V. and Maka o V.N. (2000) Su ace oxida ion o syn-
he ic py ho i e du ing we ing-d ying ea men . En i onmen al Enginee ing Science 17,
329−335.
Kallemeyn G.W., Rubin A.E. and Wasson J.T. (1991) The composi ional classi ica ion o
chond i es: V. The Ka oonda (CK) g oup o ca bonaceous chond i es. Geochimica e
Cosmochimica Ac a 55, 881–892.
Kaneda H., Takenouchi S. and Shoji T. (1986) S abili y o pen landi e in he Fe-Ni-Co-S sys em.
Mine alium Deposi a 21, 169–180.
Keil K., S oe le D., Lo e S.G. and Sco E.R.D. (1997) Cons ain s on he ole o impac hea ing
and mel ing in as e oids. Me eo i ics and Plane a y Science 32, 349–363.
Kelly D.P. and Vaughan D.J. (1983). Py ho i e-pen landi e o e ex u es: a mechanis ic app oach.
Mine alogical Magazine 47, 453–463.
Ke idge J.F. (1976) Fo ma ion o i on sulphide in sola nebula. Na u e 259, 189–190.
Ke idge J.F., Macdougall J.D. and Ma i K. (1979a) Clues o he o igin o sul ide mine als in CI
chond i es. Ea h and Plane a y Science Le e s 43, 359–367.
Ke idge J.F., MacDougall J.D. and Ca lson J. (1979b) I on-nickel sul ides in he Mu chison
me eo i e and hei ela ionship o phase Q1. Ea h and Plane a y Science Le e s 43, 1–4.
Kimu a M., G ossman J.N. and Weisbe g M.K. (2011) Fe-Ni me al and sul ide mine als in CM
146
BIBLIOGRAPHY
chond i es: An indica o o he mal his o y. Me eo i ics and Plane a y Science 46, 431–442.
Kissin S.A. and Sco S.D. (1982) Phase ela ions in ol ing py ho i e below 350 °C. Economic
Geology 77, 1739–1754.
Kissin S.A. and Sco S.D. (1972) Phase ela ions o in e media e py ho i es. Economic Geology
67, 1007–1007.
Ki ajima F., Nakamu a T., Takaoka N. and Mu ae T. (2002) E alua ing he he mal me amo phism
o CM chond i es by using he py oly ic beha io o ca bonaceous mac omolecula ma e .
Geochimica e Cosmochimica Ac a 66, 163–172.
Koppenol W.H. (1993) The cen ennial o he Fen on eac ion. F ee Radical Biology and Medicine
15, 645−651.
Kosyako V.I., Sinyako a E.F. and Shes ako V.A. (2003) Dependence o sul u ugaci y on he
composi ion o phase associa ions in he Fe-FeS-NiS-Ni sys em a 873 K. Geochemis y
In e na ional 41, 660–669.
Ko o K., Mo imo o N. and Gyobu A. (1975) The supe s uc u e o he in e media e py ho i e. I.
Pa ially diso de ed dis ibu ion o me al acancy in he 6C ype, Fe11S12. Ac a
C ys allog aphica B 31, 2759–2764.
Ko o K. and Ki amu a M. (1981) The supe s uc u e o he in e media e py ho i e. II. One-
dimensional ou -o -s ep ec o o Fe acancies in he incommensu a e s uc u e wi h
composi ional ange om Fe9S10 o Fe11S12. Ac a C ys allog aphica A 37, 301–308.
K o A.N., Amelin Y., Bland P., Ciesla F.J., Connelly J., Da is A.M., Huss G.R., Hu cheon I.D.,
Makide K., Nagashima K., Nyquis L.E., Russell S.S., Sco E.R.D., Th ane K, Yu imo H. and
Yin Q.-Z. (2009) O igin and ch onology o chond i ic componen s: A e iew. Geochimica e
Cosmochimica Ac a 73, 4963–4997.
Kuban R.-J. (1985) Poly ypes o he sys em Fe1-xS. C ys al Resea ch and Technology 20, 1649–
1656.
Kulle ud G. (1963) The mal s abili y o pen landi e. Canadian Mine alogis 7, 353–366.
Lau e a D.S., K emse D.T. and Fegley B. (1996) The a e o i on sul ide o ma ion in he sola
nebula. Ica us 122, 288–315.
Lau e a D.S., Lodde s K. and Fegley B. (1997) Expe imen al simula ions o sul ide o ma ion in
he sola nebula. Science 277, 358–360.
Lau e a D.S., Lodde s K. and Fegley B. (1998) Kamaci e sul u iza ion in he sola nebula.
Me eo i ics and Plane a y Science 33, 821–833.
Lee M.R., Bland P.A. and G aham G. (2003) P epa a ion o TEM samples by ocused ion beam
(FIB) echniques: applica ions o he s udy o clays and phyllosilica es in me eo i es.
Mine alogical Magazine 67, 581–592.
Li F. and F anzen H.F. (1996) O de ing, incommensu a ion, and phase ansi ions in py ho i e.
Pa II: A high- empe a u e X- ay powde di ac ion and he momagne ic s udy. Jou nal o
Solid S a e Chemis y 126, 108–120.
Lianxing G. and Vokes F.M. (1996) In e g ow hs o hexagonal and monoclinic py ho i es in some
sulphide o es om No way. Mine alogical Magazine 60, 303–316.
Lipschu z M.E., Zolensky M.E. and Bell M.S. (1999) New pe og aphic and ace elemen da a on
he mally me amo phosed ca bonaceous chond i es. An a c ic Me eo i e Resea ch 12, 57–57.
Lo and J.-P., Che ie V. and Sau e V. (2005) Sul ide mine alogy and edox condi ions in some
she go i es. Me eo i ics and Plane a y Science 40, 1257–1272.
Losiak A. and Velbel M.A. (2011) E apo i e o ma ion du ing wea he ing o An a c ic me eo i es-
A wea he ing census analysis based on he ANSMET da abase. Me eo i ics and Plane a y
Sciences 46, 443–459.
Lo e mose B.G. (2011) Recycling, euse and ehabili a ion o mine was es. Elemen s 7, 405–410.
147
BIBLIOGRAPHY
Lowson R.T. (1982) Aqueous oxida ion o py i e by molecula oxygen. Chemis y Re iews 82,
461−497.
Lusk J. and B ay D.M. (2002) Phase ela ions and he elec ochemical de e mina ion o sul u
ugaci y o selec ed eac ions in he Cu-Fe-S and Fe-S sys ems a 1 ba and empe a u es
be ween 185 and 460 °C. Chemical Geology 192, 227–248.
Maldonado E.M. and B ea ley A.J. (2011) Exsolu ion ex u es o py ho i e and al e a ion o
py ho i e and pen landi e in he CM2 ca bonaceous chond i es C escen , Mighei and
ALH81002 (abs ac #2271). P oceedings, 42nd Luna and Plane a y Science Con e ence.
Ma usak L.A. and Mulay L.N. (1980) Poly ypism in he ca ion-de icien i on sul ide, Fe9S10, and
he magne okine ics o he di usion p ocess a empe a u es abou he an i e o- o
e imagne ic (λ) phase ansi ion. Physical Re iew B 21, 238–244.
Mayeda T.K. and Clay on R.N. (1998) Oxygen iso ope e ec s in se pen ine dehyd a ion (abs ac
#1405). 29 h Luna and Plane a y Science Con e ence. CD-ROM.
McSween J H.Y. (1979) Al e a ion in CM ca bonaceous chond i es in e ed om modal and
chemical a ia ions in ma ix. Geochimica e Cosmochimica Ac a 43, 1761–1770.
Me zle K., Bischo A. and S ö le D. (1992) Acc e iona y dus man les in CM chond i es:
E idence o sola nebula p ocesses. Geochimica e Cosmochimica Ac a 56, 2873–2897.
Mikhlin Y.L., Tomashe ich Y.V., Pashko G.L., Oko ub A.V., Asano I.P. and Mazalo L.N.
(1998) Elec onic s uc u e o he non-equilib ium i on-de icien laye o hexagonal py ho i e.
Applied Su ace Science 125, 73−84.
Mikhlin Y.L., Va nek V., Asano I.P., Tomashe ich Y.V., Oko ub A.V., Li shi s A., Selyu in G.
and Pashko G.L. (2000) Reac i i y o py ho i e (Fe9S10) su aces: Spec oscopic s udies.
Physical Chemis y Chemical Physics 2, 4393−4398.
Mille M.K. and Russell K.F. (2007) A om p obe specimen p epa a ion wi h a dual beam
SEM/FIB mille . Ul amic oscopy 107, 761−766.
Mis a K. and Flee M.E. (1973) The chemical composi ions o syn he ic and na u al pen landi e
assemblages. Economic Geology 68, 518–539.
Moncu M.C., Jambo J.L., P acek C.J. and Blowes D.W. (2009) Mine d ainage om he
wea he ing o sul ide mine als and magne i e. Applied Geochemis y 24, 2362–2373.
Mo imo o N. and Nakazawa H. (1968) Py ho i es: syn he ics ha ing wo new supe s uc u es.
Science 161, 577–579.
Mo imo o N., Nakazawa H., Nishigucmi K. and Tokonami M. (1970) Py ho i es: S oichiome ic
Compounds wi h Composi ion Fen-1Sn (n≥8). Science 168, 964–966.
Mo imo o N., Gyobu A., Mukaiyama H. and Izawa E. (1975a) C ys allog aphy and s abili y o
py ho i es. Economic Geology 70, 824–833.
Mo imo o N., Gyobu A., Tsukuma K. and Ko o K. (1975b) Supe s uc u e and nons oichiome y
o in e media e py ho i e. Ame ican Mine alogis 60, 240–248.
Myc o J.R., Nesbi H.W. and P a A.R. (1995) X- ay pho oelec on and Auge elec on spec-
oscopy o ai -oxidized py ho i e: Dis ibu ion o oxidized species wi h dep h. Geochimica e
Cosmochimica Ac a 59, 721–733.
Nakamu a T. (2005) Pos -hyd a ion he mal me amo phism o ca bonaceous chond i es. Jou nal o
Mine alogical and Pe ological Sciences 100, 260–272.
Nakamu a T. (2006) Yama o 793321 CM chond i e: Dehyd a ed egoli h ma e ial o a hyd ous
as e oid. Ea h and Plane a y Science Le e s 242, 26–38.
Naka o A., Nakamu a T., Ki ajima F. and Noguchi T. (2008) E alua ion o dehyd a ion mechanism
du ing hea ing o hyd ous as e oids based on mine alogical and chemical analysis o na u ally
and expe imen ally hea ed CM chond i es. Ea h, Plane s, and Space 60, 855–864.
Naka o A., Nakamu a T., Noguchi T., Ahn I. and Lee J.I. (2011) The a ie y o he mal e olu ion
o p imi i e hyd ous as e oids eco ded in dehyd a ed ca bonaceous chond i es (abs ac
148
BIBLIOGRAPHY
#5416). Me eo i ics and Plane a y Science 46, A175.
Nakazawa H. and Mo imo o N. (1970) Py ho i e phase ela ions below 320 °C. P oceedings o
he Japan Academy 46, 678–683.
Nakazawa H., Mo imo o N. and Wa anabe E. (1975) Di ec obse a ion o me al acancies by
high- esolu ion elec on mic oscopy. Pa I: 4C ype py ho i e (Fe7S8). Ame ican Mine alogis
60, 359–366.
Nald e A.J., C aig J.R., and Kulle ud G. (1967) The cen al po ion o he Fe-Ni-S sys em and i s
bea ing on pen landi e exsolu ion in i on-nickel sul ide o es. Economic Geology 62, 826–847.
Na aoka H., Mi a H., Komiya M., Yoneda S., Kojima H. and Shimoyama A. (2004) A chemical
sequence o mac omolecula o ganic ma e in he CM chond i es. Me eo i ics and Plane a y
Science 39, 401–406.
Naza o M.A., Ku a G., B ands ae e F., N a los T., Chaussidon M. and Hoppe P. (2009)
Phospho us-bea ing sul ides and hei associa ions in CM chond i es. Pe ology 17, 101–123.
Nečas D. and Klape ek P. (2012) Gwyddion: an open-sou ce so wa e o SPM da a analysis. Cen-
al Eu opean Jou nal o Physics 10, 181–188.
Nesbi H.W., Schau uss A.G., Scaini M., Banc o G.M. and Sza gan R. (2001) XPS measu emen
o i e old and six old coo dina ed sul u in py ho i es and e idence o mille i e and py ho i e
su ace species. Ame ican Mine alogis 86, 318–326.
Nespolo M., Takeda H. and Fe a is G. (1997) C ys allog aphy o mica poly ypes. In Modula
Aspec s in Mine alogy, EMU No es in Mine alogy 1, 81–118 (ed. S. Me lino). Eö ös
Uni e si y P ess, Budapes , 449 p.
Nicholson R.V. and Scha e J.M. (1994) Labo a o y s udies o py ho i e oxida ion kine ics. In
En i onmen al Geochemis y o Sul ide Oxida ion (ACS Symposium Se ies) (eds. C. N. Alpe s
and D. W. Blowes), 14–30. Ame ican Chemical Socie y, Washing on, 681 p.
Nicol M.J. and Sco P.D. (1979) The kine ics and mechanism o he non-oxida i e dissolu ion o
some i on sulphides in aqueous acidic solu ions. Jou nal o he Sou h A ican Ins i u e o Min-
ing and Me allu gy 79, 298–305.
No ds om D.K. (2011) Mine wa e s: acidic o ci cumneu al. Elemen s 7, 393–398.
Nou uzi-Kho asani A., Lunn M. A., Jones I. P., Dobson P. S., Williams D. J. and As les M. G.
(1990) Su ace damage o CdTe by mechanical polishing in es iga ed by c oss-sec ional TEM.
Jou nal o C ys al G ow h 102, 1069–1073.
No iko G.V., Ego o V.K., Popo V.I. and Sipa ina L.V. (1977) Kine ics and mechanism o
ans o ma ions in i on- ich py ho i es and in oili e-py ho i e me as able assemblages.
Physics and Chemis y o Mine als 1, 1–14.
Ohmo o H. (1996) Fo ma ion o olcanogenic massi e sul ide deposi s: The Ku oko pe spec i e.
O e Geology Re iews 10, 135–177.
O'Shay T., Hossne L. R. and Dixon J. B. (1990) A modi ied hyd ogen pe oxide oxida ion me hod
o de e mina ion o po en ial acidi y in py i ic o e bu den. Jou nal o En i onmen al Quali y
19, 778–782.
Paul R.L. and Lipschu z M.E. (1990) Conso ium s udy o labile ace elemen s in some An a c ic
ca bonaceous chond i es: An a c ic and non-An a c ic me eo i e compa isons. An a c ic
Me eo i e Resea ch 3, 80–95.
Pe in D.D. (1969) Dissocia ion con an s o ino ganic acids and bases in aqueous solu ion. Pu e
and Applied Chemis y 20, 133–236.
Pie ce L. and Buseck P.R. (1974) Elec on imaging o py ho i e supe s uc u es. Science 186,
1209–1212.
Pós ai M. and Buseck P.R. (1997) Modula s uc u es in sulphides: sphale i e/wu zi e-,
py i e/ma casi e-, and py ho i e- ype mine als. In Modula Aspec s in Mine alogy, EMU No es
in Mine alogy 1, 193–235 (ed. S. Me lino). Eö ös Uni e si y P ess, Budapes , 449 p.
149

BIBLIOGRAPHY
Pós ai M. and Dódony I. (1990) Py ho i e supe s uc u es; Pa I, Fundamen al s uc u es o he
NC (N = 2, 3, 4 and 5) ype. Eu opean Jou nal o Mine alogy 2, 525–525.
Pós ai M., Sha p T. G. and Kon ny A. (2000) Py ho i e a ie ies om he 9.1 km deep bo ehole o
he KTB p ojec . Ame ican Mine alogis 85, 1406–1415.
Powell A.V., Vaquei o P., Knigh K.S., Chapon L.C. and Sánchez R.D. (2004) S uc u e and
magne ism in syn he ic py ho i e Fe7S8: A powde neu on-di ac ion s udy. Physical Re iew
B 70, 014415.
P a A.R., Mui I.J. and Nesbi H.W. (1994) X- ay pho oelec on and Auge elec on spec o-
scopic s udies o py ho i e and mechanism o ai oxida ion. Geochimica e Cosmochimica Ac a
58, 827–841.
P icha d H.M., Hu chinson D. and Fishe P.C. (2004) Pe ology and c ys alliza ion his o y o
mul iphase sul ide d ople s in a ma ic dike om U uguay: Implica ions o he o igin o Cu-Ni-
PGE sul ide deposi s. Economic Geology 99, 365–376.
Pu e z J. and Swanson L.W. (1992) Focused ion beam deposi ion o P con aining ilms. Jou nal o
Vacuum Science and Technology B 10, 2695–2699.
Pu nis A. (1975) Obse a ions on coexis ing py ho i e phases by ansmission elec on mic os-
copy. Con ibu ions o Mine alalogy and Pe olology 52, 307–313.
Ragha an V. (2004) Phase diag am e alua ions: Fe-Ni-S (i on-nickel-sul u ). Jou nal o Phase
Equilib ia and Di usion 25, 373–381.
Ramdoh P. (1950) Die E zmine alien und ih e Ve wachsungen. Akademie-Ve lag, Be lin, 827 p.
Rau H. (1976) Ene ge ics o de ec o ma ion and in e ac ion in py ho i e Fe1-xS and i s
homogenei y ange. Jou nal o Physics and Chemis y o Solids 37, 425–429.
Ricka d D. and Lu he G.W. III (2007) Chemis y o i on sul ides. Chemical Re iews 107, 514–
562.
Roche e P., Fillion G., Ma éi J.-L. and Dekke s M. J. (1990) Magne ic ansi ion a 30-34 Kel in
in py ho i e: insigh in o a widesp ead occu ence o his mine al in ocks. Ea h Plane a y Sci-
ence Le e s 98, 319–328.
Rubano S. and Mun oe P. R. (2004) FIB-induced damage in silicon. Jou nal o Mic oscopy 214,
213-221.
Rubin A.E. (1997) Mine alogy o me eo i e g oups. Me eo i ics and Plane a y Science 32, 231–
247.
Rubin A.E. and Kallemeyn G.W. (1989) Ca lisle Lakes and Allan Hills 85151: Membe s o a new
chond i e g ouple . Geochimica e Cosmochimica Ac a 53, 3035–3044.
Rubin A.E., T igo-Rod íguez J.M., Hube H. and Wasson J.T. (2007) P og essi e aqueous
al e a ion o CM ca bonaceous chond i es. Geochimica e Cosmochimica Ac a 71, 2361–2382.
Sáez R., Mo eno C., Gonzáles F. and Almodó a G.R. (2011) Black shales and massi e sul ide
deposi s: causal o casual ela ionships? Insigh s om Rammelsbe g, Tha sis, and D aa S a .
Mine alium Deposi a 46, 585–614.
Schippe s A. and Kock D. (2007) Geomic obiology o sul idic mine dumps: a sho e iew. Ad-
anced Ma e ials Resea ch 37, 71–73.
Sch y e s D., Van Tendeloo G. and Amelinckx S. (1985) On he o de ing mechanism o Ni3Mo -
A high esolu ion elec on mic oscopy s udy. Physica S a us Solidi A 87, 401–415.
Schulze H., Bischo A., Palme H., Spe el B., D eibus G. and O o J. (1994) Mine alogy and
chemis y o Rumu u i: The i s me eo i e all o he new R chond i e g oup. Me eo i ics 29,
275–286.
Schwa z E.J. and Vaughan D.J. (1972) Magne ic Phase Rela ions o Py ho i e. Jou nal o Geo-
magne ism and Geoelec ici y 24, 441–458.
Sha p W.E. (1966) Py ho i e: a common inclusion in Sou h A ican diamonds. Na u e 211, 402–
403.
150
BIBLIOGRAPHY
Shaw C.S.J. (1997) O igin o sul ide blebs in a iably me asoma ized man le xenoli hs, qua e na y
wes Ei el olcanic ield, Ge many. Canadian Mine alogis 35, 1453–1463.
Shimoyama A., Komiya M., and Ha ada K. (1991) Release o o ganic compounds om some
An a c ic CI and CM chond i es by labo a o y hea ing. An a c ic Me eo i e Resea ch 4, 247–
260.
S adelmann, P. (2008) JEMS: Ja a elec on mic oscopy so wa e. CIME-EPFL, Lausanne,
Swi ze land.
S ege H.F. (1982) Oxida ion o sul ide mine als: VII. E ec o empe a u e and ela i e humidi y
on he oxida ion o py ho i e. Chemical Geolology 35, 281–295.
Sugaki A. and Ki akaze A. (1998) High o m o pen landi e and i s he mal s abili y. Ame ican
Mine alogis 83, 133–140.
Taylo L.A. and Liu Y. (2009) Sul ide inclusions in diamonds: no monosul ide solid solu ion.
Russian Geology and Geophysics 50, 1201–1211.
Thomas J.E., Jones C.F., Skinne W.M. and Sma R.S.C. (1998) The ole o su ace sul u species
in he inhibi ion o py ho i e dissolu ion in acid condi ions. Geochimica e Cosmochimica Ac a
62, 1555–1565.
Thomas J.E., Skinne W.M. and Sma R.S.C. (2001) A mechanism o explain sudden changes in
a es and p oduc s o py ho i e dissolu ion in acid solu ion. Geochimica e Cosmochimica Ac a
65, 1–12.
Tokonami M., Nishiguchi K. and Mo imo o N. (1972) C ys al s uc u e o a monoclinic py ho i e
(Fe7S8). Ame ican Mine alogis 57, 1066–1080.
Tomeoka K., Kojima H. and Yanai K. (1989a) Yama o-82162: A new kind o CI ca bonaceous
chond i e ound in An a c ica. P oceedings o he NIPR Symposium on An a c ic Me eo i es 2,
36–54.
Tomeoka K., Kojima H., and Yanai K. (1989b) Yama o-86720: A CM ca bonaceous chond i e
ha ing expe ienced ex ensi e aqueous al e a ion and he mal me amo phism. P oceedings o he
NIPR Symposium on An a c ic Me eo i es 2, 55–74.
Tonui E.K., Zolensky M.E. and Lipschu z M. (2002) Pe og aphy, mine alogy and ace elemen
chemis y o Yama o-86029 Yama o-793321 and Lewis Cli 85332: Aqueous al e a ion and
hea ing e en s. An a c ic Me eo i e Resea ch 15, 38–58.
Tonui E.K., Zolensky M.E., Lipschu z M.E., Wang M.S. and Nakamu a T. (2003) Yama o 86029:
Aqueously al e ed and he mally me amo phosed CI-like chond i e wi h unusual ex u es.
Me eo i ics and Plane a y Science 38, 269–292.
Toulmin P. and Ba on J . P.B. (1964) A he modynamic s udy o py i e and py ho i e. Geochimica
e Cosmochimica Ac a 28, 641–671.
T eiman A.H. (2005) The nakhli e me eo i es: augi e- ich igneous ocks om Ma s. Chemie de
E de 65, 203–270.
T eiman A.H., Gleason J.D. and Boga d D.D. (2000) The SNC me eo i es a e om Ma s.
Plane a y and Space Science 48, 1213–1230.
Tsai H., Shieh Y. and Meye H.O.A. (1979) Mine alogy and 34S/32S a ios o sul ides associa ed
wi h kimbe li e, xenoli hs and diamonds. In The Man le Sample: Inclusion in Kimbe li es and
O he Volcanics, 87–103 (eds. F. R. Boyd and H.O.A. Meye ), Ame ican Geophysical Union,
Washing on, 424 p.
an Dyck D., B oddin D., Mahy J. and Amelinckx S. (1987) Elec on Di ac ion o T ansla ion
In e ace Modula ed S uc u es. Physica S a us Solidi A 103, 357–373.
an Landuy J. (1974) Shea s uc u es and c ys allog aphic shea p opaga ion. Jou nal de
Physique 35, 53–63.
an Landuy J., De Ridde R., Ge e s R. and Amelinckx, S. (1970) Di ac ion e ec s due o shea
s uc u es: A new me hod o de e mining he shea ec o . Ma e ials Resea ch Bulle in 5, 353-
151
BIBLIOGRAPHY
362.
an Landuy J., an Tendeloo G. and Amelinckx S. (1985) Elec on mic oscopy and di ac ion o
modula ed s uc u es. Pu e and Applied Chemis y 57, 1373–1382.
an Smaalen (2004) An elemen a y in oduc ion o supe space c ys allog aphy. Zei sch i ü
K is allog aphie 219, 681–691.
an Tendeloo G., Van Landuy J., Dela igne e P. and Amelinckx S. (1974) Composi ional
changes associa ed wi h pe iodic an iphase bounda ies in he ini ial s ages o o de ing in Ni3Mo.
Physica S a us Solidi A 25, 697–707.
Vaughan D.J. and C aig J.R. (1978) Mine al chemis y o me al sul ides. Camb idge Uni e si y
P ess, Camb idge, 493 p.
Vaughan D.J., Schwa z E.J. and Owens D.R. (1971). Py ho i es om he S a hcona Mine,
Sudbu y, Canada; A he momagne ic and mine alogical s udy. Economic Geology 66, 1131–
1144.
Veblen D.R. (1991) Polysoma ism and polysoma ic se ies: a e iew and applica ions. Ame ican
Mine alogis 76, 801–826.
Velbel M.A. (1988) The dis ibu ion and signi icance o e apo i ic wea he ing p oduc s on
an a c ic me eo i es. Me eo i ics 23, 151–159.
Volke C.A. and Mino A.M. (2007) Focused ion beam mic oscopy and mic omachining. MRS
Bulle in 32, 389–399.
Wang H. (2007) A e iew on p ocess- ela ed cha ac e is ics o py ho i e. Mine al P ocessing and
Ex ac i e Me allu gy Re iew 29, 1–41.
Wang H. and Sal eson I. (2005) A e iew on he mine al chemis y o he non-s oichiome ic i on
sulphide, Fe1-xS (0≤x≤0.125): polymo phs, phase ela ions and ansi ions, elec onic and mag-
ne ic s uc u es. Phase T ansi ions 78, 547–567.
Wenk H.-R. (ed.) (1976) T ansmission elec on mic oscopy in mine alogy. Sp inge -Ve lag, Be lin,
564 p.
Whi ney J.A. (1984) Fugaci ies o sul u ous gases in py ho i e-bea ing silicic magmas. Ame ican
Mine alogis 69, 68–78.
Williams D.B. and Ca e C.B. (2009) T ansmission Elec on Mic oscopy (2nd Ed.). Sp inge ,
New Yo k, 760 p.
Wi mann A., Swindle T.D., Cheek L.C., F ank E.A. and K ing D.A. (2010) Impac c a e ing on
he H chond i e pa en as e oid. Jou nal o Geophysical Resea ch 115, E07009.
Wojdy M. (2010) Fi yk: a gene al-pu pose peak i ing p og am. Jou nal o Applied C ys allog-
aphy 43, 1126–1128.
Wozniakiewicz P.J., Ishii H.A., Kea sley A.T., Bu chell M.J., Bland P.A., B adley J.P., Dai Z.,
Teslich N., Collins G.S. and Cole M.J. (2011) In es iga ion o i on sul ide impac c a e esi-
dues: A combined analysis by scanning and ansmission elec on mic oscopy. Me eo i ics and
Plane a y Science 46, 1007–1024.
Yamamo o A. and Nakazawa H. (1982) Modula ed s uc u e o he NC- ype (N = 5.5) py ho i e,
Fe1−xS. Ac a C ys allog aphica Sec ion A 38, 79–86.
Yamamo o K. and Nakamu a N. (1990) REE cha ac e is ics o Yama o-82162 and -86720
me eo i es and hei in e ence o classi ica ion. An a c ic Me eo i e Resea ch 3, 69–69.
Zega T.J., Ni le L.R., Busemann H., Hoppe P. and S oud R.M. (2007) Coo dina ed iso opic and
mine alogic analyses o plane a y ma e ials enabled by in si u li -ou wi h a ocused ion beam
scanning elec on mic oscope. Me eo i ics and Plane a y Science 42, 1373–1386.
Zolensky M.E. (1987) Tochilini e in C2 ca bonaceous chond i es: a e iew wi h sugges ions
(abs ac ). P oceedings, 18 h Luna and Plane a y Science Con e ence, 1132–1133.
Zolensky M.E. and Thomas K.L. (1995) I on and i on-nickel sul ides in chond i ic in e plane a y
dus pa icles. Geochimica e Cosmochimica Ac a 59, 4707–4712.
152
BIBLIOGRAPHY
153
Zolensky M.E., Ba e R. A. and P inz M. (1989) Pe og aphy, mine alogy, and ma ix
composi ion o Yama o-82162, a new CI2 chond i e. P oceedings, 20 h Luna and Plane a y
Science Con e ence, 1253–1254.
Zolensky M.E., P inz M., and Lipschu z M. (1991) Mine alogy and he mal his o y o Y-82162, Y-
86720, and B-7904. P oceeding, 16 h Symposium on An a c ic Me eo i es. 195–196.
Zolensky M.E., Ba e R. and B owning L. (1993) Mine alogy and composi ion o ma ix and
chond ule ims in ca bonaceous chond i es. Geochimica e Cosmochimica Ac a 57, 3123–3148.
Zolensky M.E., Mi le ehld D.W., Lipschu z M.E., Wang M.-S., Clay on R. N., Mayeda T. K.,
G ady M.M., Pillinge C. and Ba be D. (1997) CM chond i es exhibi he comple e pe ologic
ange om ype 2 o 1. Geochimica e Cosmochimica Ac a 61, 5099–5115.