Joseite

General Information:
 Chemical Formula:
Bi4(S,Te)3
 Composition:
(Molecular Weight = 1,003.77 gm)
Bismuth 83.28 % Bi
Tellurium 9.53 % Te
Sulfur 7.19 % S 
 Empirical Formula:
Bi4S2.25Te0.75
Physical Properties:
 Color:
gray or grayish black.
 Density:
8.1
 Diaphaniety:
Opaque
 Hardness:
2 - Gypsum
 Luster:
Metallic
More details...

General Information:
 Chemical Formula:
Bi4(S,Te)3
 Composition:
(Molecular Weight = 1,003.77 gm)
Bismuth 83.28 % Bi
Tellurium 9.53 % Te
Sulfur 7.19 % S 
 Empirical Formula:
Bi4S2.25Te0.75
Physical Properties:
 Cleavage:
[???] Perfect
 Color:
silver white.
 Density:
8.3
 Diaphaniety:
Opaque
 Hardness:
2 - Gypsum
 Luster:
Metallic
More details...