Cobalt pentlandite(Co, Ni, Fe)9S8c 2001-2005 Mineral Data Publishing, version 1

Crystal Data: Cubic. Point Group: 4/m 3 2/m.
separate crystals, to 4 mm.

As exsolved lamellae, granular and as

Physical Properties:
Cleavage: {100}. Hardness = n.d. VHN = 278–332 (100 g load).
D(meas.) = n.d. D(calc.) = 5.22
Optical Properties: Opaque. Color: In polished section, slightly lighter bronze-yellow thanpentlandite. Luster: Metallic.
R: (400) 36.9, (420) 41.9, (440) 45.9, (460) 49.2, (480) 51.7, (500) 53.8, (520) 55.6, (540) 57.0,(560) 58.2, (580) 59.2, (600) 60.0, (620) 60.5, (640) 61.0, (660) 61.2, (680) 61.4, (700) 61.5
Cell Data:

Space Group: F m3m. a = 9.973

Z=4

X-ray Powder Pattern: Outokumpu mine, Finland.
3.008 (100), 1.763 (100), 1.918 (80), 5.75 (60), 2.878 (60), 1.018 (60), 2.288 (50)
Chemistry:
CoNi
FeS

(1)
49.33
9.06
10.32
31.29

(2)
54.1
10.4
34.2

(3)
34.3
27.6
6.3
32.6

(4)
67.40

32.60

Total 100.00
98.7
100.8100.00(1) Varislahti deposit, Finland; corresponding to (Co6.86 Fe1.52 Ni1.27 )Σ=9.65 S8.00 . (2) Langis mine,
Canada; by electron microprobe, corresponding to (Co6.88 Ni1.33 )Σ=8.21 S8.00 . (3) Amianthus mine,South Africa; by electron microprobe, corresponding to (Co4.58 Ni3.70 Fe0.89 )Σ=9.17 S8.00 . (4) Co9 S8 .
Polymorphism & Series:
Mineral Group:
Occurrence:

Forms a series with pentlandite.

Pentlandite group.

With other sulfides and arsenides in hydrothermal deposits.

Association: Pyrite, marcasite, pyrrhotite, troilite, chalcopyrite, cubanite, bornite, chalcocite,digenite, linnaeite, siegenite, parkerite, bravoite, langisite, magnetite.
Distribution: In Finland, from the Varislahti [TL], Kuusjärvi, and Savonranta pyrrhotite
deposits and in the Outokumpu mine, northern Karelia, Finland. At Långban, Värmland,Sweden. From Vı̂lsan, Romania. In the Erglodd mine, ??, Wales. [??D8,ckMinWales??] Fromnear Eretria, Othris Mountains, and near Perivoli, Pindos Mountains, Greece. In Canada, at theLangis mine, Casey Township, Cobalt-Gowganda area, Ontario, and the Vauze mine, north ofNoranda, Quebec. From the Salamanca mine, Mendoza Province, Argentina. In the Amianthus
mine, Kaapsche Hoop, Barberton, and the Loolekop carbonatite, Phalaborwa, Transvaal, SouthAfrica. At the Talmessi mine, near Anarak, Iran. From the Mundonguara deposit, Chimoio
district, Mozambique. In Japan, at the Shimokaua mine, Hokkaido, and the Kamaishi mine, Iwate
Prefecture. On the Mid-Atlantic Ridge at 14◦ 45’N.
Name:

For the cobalt content and the relation with pentlandite.

Type Material:n.d.

References: (1) Kouva, O., M. Huhma, and Y. Vuorelainen (1959) A natural cobalt analogof pentlandite. Amer. Mineral., 44, 897–900. (2) Gellers, S. (1962) Refinement of the crystal
structure of Co9 S8 . Acta Cryst., 15, 1195–1198. (3) Stumpfl, E.F. and E.M. Clark (1964) A
natural occurrence of Co9 S8 , identified by x-ray microanalysis. Neues Jahrb. Mineral., Monatsh.,
240–245. (4) Petruk, W., D.C. Harris, and J.M. Stewart (1969) Langisite, a new mineral, andthe rare minerals cobalt pentlandite, siegenite, parkerite, and bravoite from the Langis mine,Cobalt-Gowganda area, Ontario, Canada. Can. Mineral., 9, 597–605. (5) Rajamini, V. and C.T.
Prewitt (1975) Refinement of the structure of Co9 S8 . Can. Mineral., 13, 75–78. (6) Criddle, A.J.
and C.J. Stanley, Eds. (1993) Quantitative data file for ore minerals, 3rd ed. Chapman & Hall,London, 103.
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