tellurobismuthite

{{infobox mineral | name = Tellurobismuthite | boxwidth = | boxbgcolor = | image = Tellurobismuthite-724040.jpg | imagesize = | alt = | caption = Tellurobismuthite. Locality: Kutemajärvi mine, Orivesi, Western and Inner Finland Region, Finland | category = Sulfide mineral | formula = Bi2Te3 | IMAsymbol = Tbi | molweight = | strunz = 2.DC.05 | dana = | system = Trigonal | class = Hexagonal scalenohedral (m) H-M symbol: ( 2/m) | symmetry = Rm | unit cell = a = 4.43, c = 29.91 [Å]; Z = 3 | color = Pale lead-gray; white in polished section | colour = | habit = Foliated masses and irregular plates | twinning = | cleavage = Perfect on {0001} | fracture = | tenacity = Flexible, sectile | mohs = 1.5 – 2 | luster = Metallic | streak = Lead gray | diaphaneity = Opaque | gravity = 7.815 | density = | polish = | opticalprop = | refractive = | birefringence = | pleochroism = | 2V = | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = | references =

}} Tellurobismuthite, or tellurbismuth, 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.