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 occurrenceEdit

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.

This article uses material from the Wikipedia article  Metasyntactic variable, which is released under the  Creative Commons Attribution-ShareAlike 3.0 Unported License.