Antimonpearceite

General Information:
 Chemical Formula:
(Ag,Cu)16(Sb,As)2S11
 Composition:
(Molecular Weight = 2,121.41 gm)
Copper 11.98 % Cu
Silver 61.02 % Ag
Antimony 8.61 % Sb
Arsenic 1.77 % As
Sulfur 16.63 % S 
 Empirical Formula:
Ag12Cu4Sb1.5As0.5S11
 IMA Status:
Approved IMA 1963
Physical Properties:
 Cleavage:
None
 Color:
black.
 Density:
6.33 - 6.35, Average = 6.34
 Diaphaniety:
Opaque
 Hardness:
3 - Calcite
 Luster:
Sub Metallic
 Streak:
black
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