Tellurobismuthite
Tellurobismuthite is a telluride mineral: bismuth telluride (Bi2Te3). It crystallizes in the trigonal system. There are natural cleavage planes in the (0001) direction as the crystal is effectively lamellar (layered) in that plane. The Mohs hardness is 1.5 - 2 and the specific gravity is 7.815. It is a dull grey color, which exhibits a splendent luster on fresh cleavage planes.[3]
| Tellurobismuthite | |
|---|---|
 | |
| General | |
| Category | Sulfide mineral |
| Formula (repeating unit) | Bi2Te3 |
| Strunz classification | 2.DC.05 |
| Crystal system | Trigonal |
| Crystal class | Hexagonal scalenohedral (3m) H-M symbol: (3 2/m) |
| Space group | R3m |
| Unit cell | a = 4.43, c = 29.91 [Å]; Z = 3 |
| Identification | |
| Color | Pale lead-gray; white in polished section |
| Crystal habit | Foliated masses and irregular plates |
| Cleavage | Perfect on {0001} |
| Tenacity | Flexible, sectile |
| Mohs scale hardness | 1.5 - 2 |
| Luster | Metallic |
| Streak | Lead gray |
| Diaphaneity | Opaque |
| Specific gravity | 7.815 |
| References | [1][2][3] |
Discovery and occurrence
It was first described in 1815 and type localities include the Mosnap mine in Toke, Telemark, Norway; the Little Mildred mine, Sylvanite District, Hidalgo County, New Mexico and the Boly Field Mine, Dahlonega, Lumpkin County, Georgia.[1]
It occurs in low sulfur hydrothermal gold-quartz veins and occurs with native gold, native bismuth, gold tellurides, tetradymite, altaite, chalcopyrite and pyrrhotite.[3]
See also
References
- D. M Chizhikov and V. P. Shchastlivyi, 1966, Tellurium and Tellurides, Nauka Publishing, Moscow