Argentotennantite

General Information:
 Chemical Formula:
(Ag,Cu)10(Zn,Fe)2(As,Sb)4S13
 Composition:
(Molecular Weight = 1,857.26 gm)
Zinc 5.28 % Zn
Iron 1.50 % Fe
Copper 8.55 % Cu
Silver 43.56 % Ag
Antimony 6.56 % Sb
Arsenic 12.10 % As
Sulfur 22.44 % S 
 Empirical Formula:
Ag7.5Cu2.5Zn1.5Fe2+0.5As3SbS13
 IMA Status:
Approved IMA 1984
Physical Properties:
 Cleavage:
None
 Color:
gray or black.
 Diaphaniety:
Opaque
 Hardness:
3.5 - Copper Penny
 Luster:
Resinous
 Streak:
red brown
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