Aramayoite

General Information:
 Chemical Formula:
Ag(Sb,Bi)S2
 Composition:
(Molecular Weight = 315.56 gm)
Silver 34.18 % Ag
Bismuth 16.56 % Bi
Antimony 28.94 % Sb
Sulfur 20.32 % S 
 Empirical Formula:
AgSb0.75Bi0.25S2
 Locality:
Chocoya, Province of Sud-Chichas, Potosi, Bolivia.
Physical Properties:
 Cleavage:
[???] Perfect, [???] Indistinct, [???] Indistinct
 Color:
iron black or deep blood red.
 Density:
5.6
 Diaphaniety:
Opaque
 Habits:
Pseudo Tetragonal - Crystals show a tetragonal shape., ,
 Hardness:
2.5 - Finger Nail
 Luster:
Metallic
 Streak:
black
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