Germanite
Germanite | |
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Germanite, probably from the Tsumeb Mine, Oshikoto Region, Namibia. Specimen size 5 cm | |
General | |
Category | Sulfide mineral |
Formula (repeating unit) | Cu26Ge4Fe4S32[1] |
Strunz classification | 02.CB.30 |
Dana classification | 2.9.4.2 |
Identification | |
Color | Reddish grey tarnishing to dark brown |
Crystal habit | Usually massive; rarely as minute cubic crystals |
Crystal system | Isometric hextetrahedral H-M Symbol (43m) |
Cleavage | None |
Tenacity | Brittle |
Mohs scale hardness | 4 |
Luster | Metallic |
Streak | Dark grey to black |
Diaphaneity | Opaque |
Specific gravity | 4.4 to 4.6 |
Other characteristics | Cell data: a = 10.585 Å Z = 1[2] |
References | [3][4] |
Germanite is a rare copper iron germanium sulfide mineral, Cu26Fe4Ge4S32. It was first discovered in 1922, and named for its germanium content.[2] It is only a minor source of this important semiconductor element, which is mainly derived from the processing of the zinc sulfide mineral sphalerite.[5] Germanite contains gallium, zinc, molybdenum, arsenic, and vanadium as impurities.[2]
Its type locality is the Tsumeb Mine in Namibia where it occurs in a hydrothermal polymetallic ore deposit in dolostone in association with renierite, pyrite, tennantite, enargite, galena, sphalerite, digenite, bornite and chalcopyrite.[4] It has also been reported from Argentina, Armenia, Bulgaria, Cuba, Democratic Republic of Congo (Zaire), Finland, France, Greece, Japan, Republic of Congo (Brazzaville), Russia and the United States.[2]
X-Ray Powder Diffraction[6] | ||||||||
---|---|---|---|---|---|---|---|---|
d spacing | 3.05 | 2.65 | 1.87 | 1.60 | 1.32 | 1.21 | 1.08 | 1.02 |
relative intensity | 10 | 1 | 7 | 4 | 1 | 2 | 2 | 1 |
References
- ↑ American Mineralogist (1984) 69:943-947
- 1 2 3 4 http://www.mindat.org/min-1681.html Mindat.org
- ↑ http://webmineral.com/data/Germanite.shtml Webmineral
- 1 2 http://rruff.geo.arizona.edu/doclib/hom/germanite.pdf Handbook of Mineralogy
- ↑ U.S. Geological Survey (2008), "Germanium—Statistics and Information", U.S. Geological Survey, Mineral Commodity Summaries http://minerals.usgs.gov/minerals/pubs/commodity/germanium/
- ↑ Dana's New Mineralogy, 8th edition, Gaines et al., Wiley
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