Germanite

Cu13 Fe2 Ge2 S16
c 2001-2005 Mineral Data Publishing, version 1Crystal Data: Cubic. Point Group: 43m. Cubic crystals, rarely to 3 cm [check 3 cm inGebhardt??!!formerly ”tiny”]; commonly massive, intergrown with reniérite.
Physical Properties:D(calc.) = 4.30

Tenacity: Brittle. Hardness = 4 VHN = n.d. D(meas.) = 4.46–4.59

Optical Properties: Opaque. Color: Reddish gray, tarnishes to a dull brown; in polishedsection, pinkish gray. Streak: Dark gray to black. Luster: Metallic, dull.
R: (400) 21.9, (420) 21.5, (440) 21.1, (460) 20.6, (480) 20.0, (500) 19.6, (520) 19.7, (540) 20.2,(560) 21.0, (580) 21.9, (600) 22.8, (620) 23.8, (640) 24.7, (660) 25.5, (680) 26.2, (700) 26.8
Cell Data:

Space Group: F 43n. a = 10.5862(5)Z=2

X-ray Powder Pattern: Tsumeb, Namibia.
3.054 (100), 1.870 (72), 1.5954 (40), 1.0802 (20), 1.2141 (16), 2.645 (12), 1.3229 (10)Chemistry:
CuFeZnMoW

(1)
45.5
6.8
1.2
0.5
0.0

(2)
45.06
8.14
1.510.26
0.33(3)
51.76
7.00

VGeGaAsS

(1)
0.0
9.6
0.0
3.3
31.6

(2)
0.12
9.61
0.65
2.97
31.96

(3)
9.10

32.14

Total 98.5
100.21100.00(1) Tsumeb, Namibia; by electron microprobe, corresponds to (Cu11.63 Zn0.30 )Σ=11.93 Fe3+
1.98
(Ge2.15 As0.72 Mo0.08 )Σ=2.95 S16.00 . (2) Do.; by electron microprobe, average of 30 analyses;
3+
corresponds to (Cu11.38 Zn0.37 Fe2+0.34 )Σ=12.09 Fe2.00 (Ge2.12 As0.64 Ga0.06 Mo0.04 V0.04 W0.03 )Σ=2.93 S16.00 .
1+2+3+4+(3) Cu8 Cu5 Fe2 Ge2 S16 ; Mo-, V-, and W-rich varities are known.
Mineral Group:Colusite group.

Occurrence: In primary Cu–Pb–Zn ores in a dolostone-hosted hydrothermal polymetallic ore
deposit (Tsumeb, Namibia).
Association:chalcopyrite.

Reniérite, pyrite, tennantite, enargite, galena, sphalerite, digenite, bornite,

Distribution: From Tsumeb, Namibia [TL]. At M’Passa, 150 km west of Brazzaville, Congo
Republic. From Kipushi, 28 km southwest of Lubumbashi, Katanga Province, Congo (ShabaProvince, Zaire). In the USA, at the Inexco #1 mine, Jamestown, Boulder Co., Colorado; andin the Ruby Creek deposit, Brooks Range, near Bornite, Alaska. In Cuba, from Pinar del Rio
Province. In Bulgaria, at the Radka deposit, Pazardzhik. From Dastakert, Armenia. At Bor,Serbia. From the Bancairoun mine, Alpes-Maritimes, France. At Weisloch, ??, Germany. InRussia, from Vaygach, Arkhangel’sk, and in the Noril’sk region, western Siberia; at the Vaigach
and Sibai deposits, Ural Mountains. In the Shakanai mine, Akita Prefecture, Japan.
Name:

For the germanium content of the mineral.

Type Material:

The Natural History Museum, London, England, 1922,1180.

References: (1) Palache, C., H. Berman, and C. Frondel (1944) Dana’s system of mineralogy,(7th edition), v. I, 385–386. (2) Sclar, C.B. and B.H. Geier (1954) The paragenetic relationships ofgermanite and reniérite from Tsumeb, South West Africa. Econ. Geol., 52, 612–631. (3) Springer,G. (1969) Microanalytical investigations into germanite, renierite, briartite, and gallite. Neues
Jahrb. Mineral., Monatsh., 435–441. (4) Geier, B.H. and J. Otteman (1970) New secondary
tin-germanium and primary tungsten-(molybdenum-, vanadium-) germanium minerals from theTsumeb ore deposit. Neues Jahrb. Mineral., Abh., 114, 89–107. (5) Tettenhorst, R.T. and C.E.
Corbató (1984) Crystal structure of germanite, Cu26 Ge4 Fe4 S32 , determined by x-ray powder
diffraction. Amer. Mineral., 69, 943–947. (6) Spiridonov, E.M. (1987) On the composition ofgermanite. Doklady Acad. Nauk SSSR, 295, 477–481 (in Russian). (7) Criddle, A.J. and C.J.
Stanley, Eds. (1993) Quantitative data file for ore minerals, 3rd ed. Chapman & Hall, London,
193.
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