Baumhauerite

General Information:
 Chemical Formula:
Pb3As4S9
 Composition:
(Molecular Weight = 1,209.88 gm)
Arsenic 24.77 % As
Lead 51.38 % Pb
Sulfur 23.85 % S 
 Empirical Formula:
Pb3As4S9
 Locality:
Binnental, Valais, Switzerland.
Physical Properties:
 Cleavage:
[???] Perfect
 Color:
lead gray or steel gray.
 Density:
5.33
 Diaphaniety:
Opaque
 Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., ,
 Hardness:
3 - Calcite
 Luster:
Metallic
 Streak:
chocolate brown
More details...

General Information:
 Chemical Formula:
Pb3As4S9
 Composition:
(Molecular Weight = 1,209.88 gm)
Arsenic 24.77 % As
Lead 51.38 % Pb
Sulfur 23.85 % S 
 Empirical Formula:
Pb3As4S9
Physical Properties:
 Color:
steel gray.
 Diaphaniety:
Opaque
 Habits:
Crystalline - Fine - Occurs as well-formed fine sized crystals., ,
 Hardness:
3 - Calcite
 Luster:
Metallic
 Streak:
reddish brown
More details...