Galenobismutite

General Information:
 Chemical Formula:
PbBi2S4
 Composition:
(Molecular Weight = 753.42 gm)
Bismuth 55.47 % Bi
Lead 27.50 % Pb
Sulfur 17.02 % S 
 Empirical Formula:
PbBi2S4
 Environment:
Vermland, Sweden.
 Locality:
Nordmark,
 Name Origin:
Named after its chemical composition.
Physical Properties:
 Cleavage:
[110] Good
 Color:
lead gray, gray, light gray, or tin white.
 Density:
6.9 - 7.1, Average = 7
 Diaphaniety:
Opaque
 Habits:
Columnar - Forms columns, Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Massive - Uniformly indistinguishable crystals forming large masses.
 Hardness:
2.5-3 - Finger Nail-Calcite
 Luminescence:
Non-fluorescent.
 Luster:
Metallic
 Streak:
gray black
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