Cannilinn M ineralogist"
Vol. 12, pp. 5160 (1973)
MATTAGAMITE AND TEI.LURANTIMONY, TWO NEW TEIIURIDE MINERATS FROM
MATTAGAMI IAKE AAINE,MATAGAMI AREA, QUEBEC*
R. I. THORPE'arvoD. C. HARRIS'
AegrRACr
Mattagamite is a new mineral with the composition
Co.saFe.s7Te2.66.
The name is for the locality and is
to be applied to the end member CoTe2. The analyzed
material is a ferroan mattagamite. The mineral isorthorhombic;_ the unit-cell for CoTe2 is a 5.31,
b 6.31, c 3.894 whereas for FeTe2 (frohbergite) it fu
a 5.X), b 6.21 c 3.864. The strongest lines on ttre
x,-rau power pattern are 3.31(3), 2.805(10), 2.703(8),2.066(6), 1.843(4), 1.583(3), t.514(2), 1.354(2)4. The
mineral occursas equidimensionalgrains (110 microns
or less) isolated in altaite and as irregular rims (430
microns) on pyrrhotite and chalcopyr.ite in contact
with altaite. Under reflected light the mineral is violet,
particularly in contrast to the pink of cobaltite. Anisotropism is weal<, varying from a pinkish violet tograyish violet. Reflectance measuraamts at 470, 546,
589 and 650 nm gave 53.1, 51.4 51.7, atd 52,7%.
Micro-indentation hardness values are 383, 4M kg/
nrmz for a 25 g load and 630 kg/mmz for a t5 g loid"
Tellurantimony is a new mineral with the composition Sb1.s1Tq. The name is for the composition,
Sb2Tq, in analogy *idt lsllurfismut\
Bi2Tq, withn'hich it is isostructural. The mineral is horagonal(R5rn) ; the unit-cell is a 42.ffi, c 30.516A. The
strongest lines on the x-rag powder pattem arealtaite*pyrrhotitegrain boundary.Mi*oprobe analysis
gave a formula of Age.eSbl.oT%.0.
Imnooucrton

The new minerals described here occur in asmall zone of telluride ore within the Mattagar:ri
Lake mine in the Matagami area, Quebec.This
fype of telluride zone is not known to occur elsewhere in association with the type of massive
sulphide deposit which forms the main orebody.
$amples from the telluride zone were obtainedby one of us (R.I.T.) during a visit to Mattagami Lake mine on October 5, I97I. X-ray
powder pattern identification of the bright metallic mineral in these samples proved it to bealtaite. Two new telhuide minerals, tellurantimony and mattagamitg were detected druing
subsequent microscopie and electron microprobe
study of a number of polished sections.Additional specimens \Meresubsequently very kindly
supplied by geologistsat the mine.
The new minerals and names were approvedby the Commission on New Minerals and Mineral Names, I.M.A. The name mattagamite (MA3.156(10),2.W(7), z.tn(q, 1.980(7),1.?67(6), TOG A-MIT) is proposed for the locality, Mat1.57(5),1.468(4),1.359(5)4.
The mineraloccursin tagami Lake, Quebec, and is to be applied toaltaite as lath-shapeil crystals up ro t?5 microns wide
the end member CoTez; the analyzed materialand 350 microns long, but more frequently as laths
is a ferroan mattagamite. The name tellurantirrp to 40 microns qride Under reflected light themony is for the composition, SbzTes, in analogy
mineral shows weak pleochroism witl mlours fromwith telhubismuth, BizTeg,with which it is isopink to cream. Anisotropism is moderatg varying
lrom pink to dark grey. Reflectance measurements structural. Type material is presewed in the NaaI 470, 546,589 and 650 nm gave 65.1, 63.6 63.8 and tional Mineral Collection, Geological Suwey of
63il/6. Miuo-indentation hardness values range from
Canada, Ottawa and the mineral collections of
39.6-61.3(au &.8) kdmmz with a 25 g load.
the Royal Ontario Museum (ROM M31956,
M31957, M31958), Toronto, Ontario.
Subsequent to the initial study, an antimonian marThe Mattagami Lake mine is in Galinee
tagamite and an unknown Ag-Sb telluride were identified. The antimonian mattagamite occurs rimming
Township, 5 miles southrrest of the tovm of
pyrrhotite in contact with altaite and contains up to
Matagami, Quebec. The main orebody is a large
4.5 weight per cent antimony. The antimony corrtent zinc-rich deposit of the stratiform massive sulhas been lound to vary inversely with iron.-The unphide type in Archean volcanics which range
known telluride occurs as a 15 micron bleb along anfrom rhyodacite to andesite in composition(Roberts 1966; Sharpe 1968).This We of Zn* Mineral Research Program - Sulphiile
Researctr Cu (Pb-Ag) massivesulphide deposit is of wideContribution No. 74
spread occrurence in the volcanic belts of the_ l. Geologica! Survey of Canadq Department ofPrecambrian Shield, and a volcanogenic origin
Energy, Mines & Resources,601 Booth Street, Ottawa,is widely acceptd. The magnesian metasomaOntario.
tism, as representedby chlorite, talc and tremolite
2 Mineral Sciences Dvision" Mines Brand:. Department of Energy, Mines & Resources, S5.5 boothin the alteration zone of the deposit (Robens
Streeg Ottawa, Ontario.
I'966), is a conuuon characteristic of this type

55

56

TrrE caNADraNMINERALOGISTof deposit. About 8.5 million tons had been
mined at the Mattagami Lake mine to the endof 1969and res€rvesrverethen about 17.3million
tons grading 9.6f6 2n,0.69/6 C;.t, 1.08ozlton Ag
and 0.012 oz/ton Au (Financial Posq Survey ofMines 1971).

the new minerals tellurantimony and mattagamite.
The magnetite occurs as equant grains thatare rounded and irregular to subhedral in shape,
and as composite grains with subhedral form
against silicate gangue and other minerals. Inclusions of altaitg cobaltite and gangueare comThe telluride zone in the mine occurs on the
Chalcopyrite and sphalerite are present inmon.
825 subJevel and the 870 level. A drill intersmall amounts in mirst specimens,but in certain
section which assayed4S4 oz/ton Ag for a le"Sthof 13 ft may indicate an extension of the zone specimens both minerals are much more abundown to the 925 sub-level. The telluride zone dant. Chalcopyrite showseither a mutual boundis only about one foot wide and has been traced ary relationship with altaite, or gives the appearance of having crystallized earlier. Sphalerite
for a lengtl of about 100 ft and vfiically forabout 60 ft. The zone is conformable with the contains fine blebs of chalcopyrite which are
schistosity of the rock and some ore minerals are generally interpreted as having formed by exsoludisseminated in the sheared rock for a short tion. Cobaltite is a relatively abundant mineralin the ore. It forms rounded and subhedral
distance on either side of the main bodv. The
telluride zone ocrurs partly within massive sul- grains about 0.1 to 2 mm in diameter and also
phide ore and partly within chloritized por- occurs as very small scatteredto tightly-packed
phyritic metarhyolite. The contact between the quant grains in an altaite matrix. In a numberof casesskeletal cobaltite grains in altaite weremassive sulphides and the drloritized porphyritic
observed. Pyrrhotite is a common, but not abunmetarhyolite is described as gradational, witl
sulphides occurring more in the form of stringers dant, constituent that occurs,in part, as lenticuin the latter unit. The telluride zone lies beneath lar massesalong the schistosity.In general theand roughly parallel to a post-ore metadiabase pyrrhotite shows textural relationships similar to.dike which strikes northwest and dips 70o to the t}ose of chalcopyrite, and contains cobaltite andnortheast The telluride zone may have been altaite inclusions. Pyrite in equidimensional
truncated (displaced?) by the metadiabasedike grains of medium to large size are relatively
above the 825 sub-level and also below tlee 925 abundant in some specimens. In a few cases
sub-level. From the general relationships de. small grains of plrite were observedin pyrrhotite
scribed abovq it seemsthat the tellwide zone and chalcopyrite. Hessite is a rare constituent
was formed within the general alteration pipe of the ore, but is the phase accounting for thewhich marks a hydrothermal vent qystem in the silver indicated by the assayresults. The largest
footwall ro&s. Sudr alteration pipes are known grains of hessitg up to 470 microns long by 55
to occur immediately beneath many massivesul- to 115 microns wide, were observedin relatively
phide deposits of the type representedby the large areas of massive altaite. Although largely
surrounded by altaite, these large grains aremain orebody (Gilmour 1965; Roscoe 1965).
often in clntact with chalcopyrite. Grains ofhessite about 20 by 5 microns and ranging dovm
l/InvuRAlocy awp Tsrrwnrs
to a few microns across are more cotnmon.
oF THE Trr"r.unms ORE
Tellurantimony commonly occurs as lathfusay data grve some idea of the mineralogy
shaped grains in an altaite matrix. At leastof the zone. Samples of the telluride ore have scattered small laths of the mineral appear to bepresentin all large massesof altaite. Mattagamite
assayedas high as 8.26/o Zn, LI.06/6 Pb, I.l3%
Cu, and 16.82oz/ton Ag. A representative sample was found in only one specimen,which containedof the material contained II.54 oz/ton Ag and fairly abundant chalcopyrite and sphalerite. A
0.021 oz/ton Au.
number of polished sections were prepared fromThe gangue in the telluride ore is generally this specimen.
very rich in talq although chlorite in place of
Oeucaq Pnvsrcar- err,o Crruurcer. Pnopnnrrss
talc is present in some specimens. Magnetite iscommonly a prominent constituent of the ore;
The samples were mounted in cold-setting
Robsts (1966) has noted for tle mine generally plastig polished on lead laps and lightly buffedthat magnetite is a cornmon constituent of mag- on a cloth lap using minus 0.2-p alumina. The
nesium (talc)-rich schist. Altaite is the most reflectance values were obtained with a Leitz
MPE microscope photometer equipped with acornmon ore mineral in the telluride zong but
sphalerite and chalcopyrite are abundant in some Dumont, type-M67 photomultiplier tube, two
specimens. Other opaque minerals that are pre- six-volt storage batteries connected in parallel,
sent are cobaltitg pyrrhotite, pyrite, hessite, andi . and a Veril 8200 continuous-band interferencefoIATTAGAMITE AND TELLURANTIMONY

filter. A calibrated silicon specimen (N2538.42)
issuedby I.M.A. Commission on Ore Microscopy,
was used as a reference standard. The microhardness values were determined with a Leiz
Durimet hardness tester equipped with polafizing
filters and rotating stage.
The compositions were determined using aMaterials Analysis Company model 400 electronprobe microanalyzer. Pure metals were used as
standards and corrections were applied using
Edition VII of the progam by Rucklidge (1967).
X-ray diffraction powder data were obtainedby the film method using a 57.3 mm Gandolfi
calnera. Material suitable for single crystal study
was not available. However, the powder patterns
are identical to the synthetic members fromwhich the unit cell dimensions were determined. Synthetic CoTez and FeTez were formedby reacting high-purity elements in evacuatedquartz tubes. X-ray data for pure SbzTes arelisted in PDF 15-874.
Mattagamite

FROI\{ OUEBEC

57

The x-ray diffraction data for mattagamite
and slinthetic CoTez are given in Table 3.
Tengn6r (1938) detentrined the structure of s)"nthetic CoTez to be orthorhombiq like FeTez,with o 5.31, b 6.31, c 3.894, whereas FeTez(frohbergite) has a 5.29, b 6.n, c 3.864 (Berry& Thompson 1962).For synthetic CoTeepreparedin this study the unit cell pardneters obtainedwith 114.6 mm Debye.Scherrercamera and refined by a least-square-computer program are
a 5.305, b 6.289, c 3.8664. The pattem of mattagamite was not suitable for unit cell determinations.
Tellurantimony
The mineral occurs in altaite as lath-shaped
crystalsup to 175 microns wide and 350 microns
long, but more frequently as laths 40 microns
wide and less (Figs. 3, 4). In reflected lighq with
oil immersion, the mineral shows weak pleochroism with colours from pinl to cream. The
mineral in contact with cobaltite has a creamy
pink appearance,whereascobaltite appearsdarker
pink. Anisotropism is moderate, varying frompink to dark grey. Reflectanceand microhardness
measurementsare given in Table l. Lr at least
some orientations the mineral has a greater
polishing hardnessthan the host altaite. Twinning perpendicular to the elongation axis of thelaths was commonly observed.

The mineral occurs as equidimensional andrarely as blade.like grains isolated in altaite(Fig. 1), and as irregular rims on pyrrhotite andchalcopylite in contact with altaite (Fig. 2). The
rims range hom a few microns to 30 microns inwidth whereasthe largest equidimensional grain
is 110 microns. Hessite is sometimes associatedElectron-probemicroanalysesof tellurantimony
with the mattagamite rims. ftr reflected lightunder oil immersion, the colour is violet, parti- are given in Table 2. The formula for tellurantimony is Sbr.erTes.ooor ideally SbzTeg.Using
cularly in contrast to the pink of cobaltite. Animetal standards,it is not possible to determine
sotropism is weak, varying from a pinkish-violet
to greyish-violet. Microhardness determinations whether the mineral has a slight deficiency inand reflectance measurelnentsfor the four stand- antimony as suggestedby the analysis.
ard wavelengths are given in Table 1.
PROBE
MICROANALYSES
2. ELECTRON
TABLE
The results of the electron-probemicroanalysis for the tlree largest grains are given in
Table 2. The averageformula for mattagamite is {eEqss!]Ee
'110u
AV.
40u
60u
G r a i ns i z e
Co.saFe.s?Te2.oo.
I0.3
9.9
9.8
11.1
Co
6.7
7.1
HARDNESS
7. 0
TABLEI. REFLECTANCE
ANDMICRO.INDENTATION
6.0
Fe
82.+
82.3
82.4
82.6
Te
t'laEqgnCIj.le.
Tel I urantimony
99,4
99.3
Total wt. % 99.7 99.2
l,JaveI ength

Rangeof 9 Mean Rangeof 13[Easuremen!srneasurements

470 nm

6 0 . 4 - 7 1. I

589 nm5t . 7-54.3 53. r
50.0-52.6 5I.4
50.3-52.6 51.7

650 nm

5U.6-9J.v

546 nmro-tZ.I

59.8-67.9

63.6

6l.5-67.9

63.8

61.5-68.7

63.7

l3

i ndentat l on

hardness( t<g/nnnz)

Formula Co.54F..37T.2.00

VHNrU=3s3'4t*

4 0 . 2 - 7 3 . 9( a v .
V H N 2 (55 g r a i n s ) :3 9 . 6 - 6 1 . 3( a v . 4 9 . 8 )Tel 1urantimonysb
Bi

8cns9.

37.s
0.3

J5.U-JU.Z

6t.B

Te
I old I Wt.

Av. (B grains)

7o

oo6

Formula Sbl.9lT.3.0

0. 2 - 0 . 3
61.0-62.6

58

TI{E

CANADIAN

MINERALOCIST

Frc. 1. Large equant $ain of mattagamite (M) in altaite (A) with associatedeuhedral crystals ofcobaltite (C) and hessite (H).
Frc. 2. Mattagamite (M) as an equant grain in altaite (A) and as a partial rim between chalcopyrite (C) and altaite, and between &alcopyrite and pyrrhotite (PO). The dark areas are pits.
Scale should read 10 and 20" not 100 and 200.
Frc. 3. Typical lath of tellurantimony (T) in altaite (A). The bright areas are internal reflections
from gangue minerals. Nicols partly crossed.
Frc. 4. Laths of tellurantimony (T) in altaite (A) with pyrrhotite (PO) grains at various degrees
of extinction. Nicols partly crossed.

MATTAGAMITE AND TELLUM1YTIMONY

The x-ray diffraction data for tellwantimony
are given in Table 3 and compared w.ith thoseof synthetic SbzTeg, with which it is identical.
The unit cell dimensions for tellurantimony
obtained with a 57.3 mm Gandolfi camerausing
Fe-filtered Co radiation and refined by a leastsquare compurer program are a 4.258, c 30.5164.
TABLE3.
Synthetic

l'lattagamite

a'5.305, b-6.289, a=3.866A!

hkl

daula.Ao /est.

dr"ur.A'

rest.

0lI

3.293

3,294
3.224
3 .I 2 5
2.805
2,707
2,667
2,44e
2,225
2,07i
2,034
1,949
'I
.904
i.850
I.800

3

3

l0l
t]I
't20
200
210
121
211
220
130
012
221
112
310
230
040
202
320
212
321
'l4t
132
2N
400
410
003
331
4t I
042
322
340
123
203
213
341
242

3.124
2,798
2.705
2.653
2,M4
2.?16
2.066
2,027
1.950
1.848
1.796
1.745
1.702
I.645
1,572
1.562
1.54t
I.516
1.432
1.404
I.373
1.352
1.326
1,298
1.289
1,276
I.230
1,?20
1.205
1.175
1 .t 6 3'1.159
l.'t401.124
I.108*PDF l5-874

4
I
l0
3
I
I
6
2
4
112
5
3
4
3
3
8
1
3
3
1
2
I
5
2
2
3
112
2
5
I
6
1/2
112
3
3
4

Acrrowr-mcElvrENTS
The authors wish to acknowledge the interest
and assistanceof the geological staff of Mattagami Lake Mines; namely A. Wilson, B. Kerr,and G. Gagnon. We are also grateful for theassistancegiven by the following personnel ofthe Mineral SciencesDivision : J. Stewart for the

X-MY DIFFRACTIONDATAOF MTTAGAI4ITE
AI{DTELLUMNTIMONY

CoTe,

112

OY

FROM QUEBEC

l0
84n.ts.A"
J.JI

2.805
2.703

6

2,066

4

1.843

l./fl

'I

.708
1,644
l.Jtz

J

I .583

2

I .5 t.1

I .50+

I .547
1.5t8
1.438
I .406
1.379
'l
.357

2

L354

r ??n

I .300
l.zd5

1.271
1,239
1.2t3
I .200
1.170
1.163
'I
.155
t.t48
1.128
l.l 14

2
2

2

'I

.205

't.168'I.108

Synthetic SbrTer*

Tel l urantimony

a.4.262' c=30.450Ao

a=4.258,c=30.516A'

hkl dcalc.Ao/rl

4n"u..A' /est.

003 10.I500 2 10.16
4
5.08
006 5.0750
J.SJ
009 3.3833 O
3.321
014 3.3212 2
0 1 5 3 . 1 5 6 5 1 0 0 3 . 15 7
0 1 7 2 . a 1 M <l
2.815
2
2.651
018 2.6497
2.349
0 1 . 1 0 2 . 3 4 8 9 35
2.215
0I.il 2.2146 62,t30
1 1 0 2 . 1 3 1 0 25
2.030
0 0 .t 5 2 . 0 3 0 0 4
1.977
01,13 1.9777 4
1.964
I 16 I.9648
2|.875
01.141.8739 4
I 1 9 1 . 8 0 1 3 2- I.804'1,7662 l 0
1,76602500.181.6er7l 2
1,692
I
0 l . 1 6 r . 6 9 1[5tl.ool
028 I.6606 .<1
0t.'r7 1.6115'l0e.10 .57t|:r't.5378
0l.tI
0t.19 1.4700
00.21 1.4500-

2
8
2
8

?

0r.20r.407s'l 2)
02.14r.4o72t
125 t.3598
1 1 . 1 81 . 3 2 4 9
12.10 1,2683
01.23 1.2M2
030 1.2303

8
'2
6
2
2
2
<l
t

1.6il
't.578

2
't
'10
'I

4*r..A"

|
7
1
I
1
7

3.389
3.327
3.156
2.8i0
2.659
2.348
2.211
2,129
2.030
I.980

2

1,tt696't.769

I

1.699

5

1.577

1.537
I.470
1.450

4

1,468

1.408

1

1.408

1.35971.3249I .2683
1.2462L2303
1.2102
1.19881.1742

5
2
2

1.359
1,327
1,266

1

1.230

1

1 .1 9 6

t
I
I
I

1.008
0.994
0.969
0.959

60

THE

CANADIAN

MINERALOGIST,c-ray work, L.J. Cabri for synthetic work, R.
Pinard for the photomicrographsand P. O'Donovan for the polished sections.

Fe/Co * Fe X 100: 50 atomic percent, antimony is absent. This would represent an ironcontent of 8.93 wt%. This value may be highsince the analysis of mattagamite in the earlier
APPENDUM : Antimonian mattagamite andstudy gave 7.L wt% Fe, with no antimony.
an unknown Ag-Sb-telluride
Similarly a plot with Sb/Te + Sb X 100 onln the course of preparation and study of the logarithmic scale indicates tlat iron is not
additional polished sections of the altaite-riih
present when this ratio exceeds30 to 39 atomic
specimens collected from a drift on the 825 ft
percent (that is, a maximum of about 30.7 w|%
level of tlre Mattagami Lake mine, electron Sb). However, the antimony-rich mattagamite
microprobe analysesrevealed that in many cases in section 825 suggeststhat the most antimonythe new mineral mattagamite is also antimony- rich phase may have Sb/Te * Sb X 100 : 50
bearing. In nearly all equant grains of mattaga- atomic percent (about 39.5 wt% Sb). The highmite isolated in altaitg the mode of occurrence est antimony content measured for the mineral
for which compositional data were originally ob- is 29.5 vrt%.
tained, aatimony was not detected.However, in
Ir addition, another unknown telluride has
its other mode of occulrence, as rims on pyr- been identified in the ore. The mineral occurs
rhotite in contact with altaitg mattagamite con- as a small bleb (15 microns) along the contact
tains antimony and as much as 29.5 weight of pynhotite and altaite. The mineral is anisopercent has been measured.The antimony con- tropic and has a pinkish tint. Eleckon microprobe
tent of mattagamite has been found to vary analysis gave Ag 20.1, Sb 25.3, Te 53.1 total
inversely with its iron content. A semi-logarith98.6wt%, equivalent to the formula Ago.sSbr.o
mic plot of the compositional data is presented Tez.o.The mineral is too sparsefor proper charin Figwe 5. It can be seenthat an approximately acterization of the phase.
inverse exponential relationship exists between
The new compositional data of mattagamite
the antimony and iron contents of the mineral.
The roughly linear relationship for the composi- indicate that while, in atomic proportion, cobalt
tion of grains analyzed in section G (Fie. 5) always exceedsiron and tellurium always exceeds
indicates that when the iron content exceeds antimony, the measured compositions are forrelatively iron-rich (ferroan mattagamite), antimony-rich (antimonian mattagamite), and intermediate solid solution phases.That is, the postu\*[
oseclion M\
lated ideal composition of mattagamite, CoTez,\
aSection H
A Section G
is not closely approximated.It seemslikely that\
I
Ssction 825C\
in antimony-deficient assemblages one may(TobleAnolYses2)x\
expect compositionsnearer the ideal.
q

"I
*f

\\
\ \ \ \."\ .x \.
\ \ .\ \
\\

\o\

^ ,ol
o
-t
X

l8 16r
3l+ t

'*"f

\

\\

\

.I

.\
\^' r \
tt\
.;\

"f

"l

|

2

3

4
6;f1g

5 6 789rO

15 20

9r:J
30 40 50x roo (Aromic)

Frc. 5. Semi-logarithmic plot showing the inverse relationship between the iron and antimony contents
of mattagamite. The composition5 measured forgrains in individual polished sections are distinguished and the compositional relationships lor
sections G and H are approximately represented
by the solid and dashed lineso respectively.

RrrsarNcEs
Brnnr, L.G. & Tnoumory RM. (1962): X-ray
powder data for ore minerals: The PeacockAtlas.
Geol. Soc.Arner.Mem. E5.
Gnuou& P. (1965): The origin of the massivezulphide mineralizationin the Norandadistricq North'\restem
Quebec.GeoI.Assoc.Can. Proc.16 63-81.
Roannrs,R.H. (1966): The geology of Mattagami
Lake mine, Galinee Township, Quebec Unpubl.
Ph.D. thesis,McGill Unioersitg.
Roscoq S.M. (1965): Geochemicaland isotropic
studies,Norandaand Matagamiareas;Symposiumon Strata-Bound
Sulphides.
Trans.Can. Inst.Mining
Met. 68, 279-285.
Rucrttocr, I, (1967): A computerpmgramfor processingmicroprobedata. l. Geol. 75, 126.
Suallr, J.L (1968): Geologyand sulphidedepositsof the Matagami area,Abitibi-East County.Quebec
Dept. of Nat. Res.GeoI. Rept. t37' 122.
Turrolfu S. vow (1938): Uben Diselenidermd vonEisen,Kobalt und Nickel. Z. Anorg. AIle. Chem,
239, 126-132.
Illanuscriptreceiueillme, 1972,