Bismutite
Chemical Formula	Bi2(CO3)O2
Species	Carbonates
Crystal System	Orthorhombic
Mohs Scale	2-3
Specific Gravity	6.7-7.4
Color	Yellow to brown, greenish, green-grey, grey or black
Streak	Grey
Luster	Vitreous, Pearly, Dull, Earthy
Refractive Index	n = 2.120 - 2.150 n = 2.120 - 2.300
Diaphaneity	Transparent, Translucent
Cleavage	Distinct/GoodOn .
Crystal Habit：Very rare as platy crystals; typically radially fibrous to spheroidal, in crusts and earthy to dense massive aggregates
Geological Setting：Oxidation zones of Bi-bearing ore deposits such as hydrothermal veins and in pegmatites containing bismuthinite and native bismuth.