Vaughanite

General Information:
 Chemical Formula:
TlHgSb4S7
 Composition:
(Molecular Weight = 1,116.44 gm)
Thallium 18.31 % Tl
Mercury 17.97 % Hg
Antimony 43.62 % Sb
Sulfur 20.11 % S 
 Empirical Formula:
TlHgSb4S7
 IMA Status:
Approved IMA
 Locality:
Hemlo gold deposit, near Marathon, Ontario, Canada.
 Name Origin:
Named for David J. Vaughan (1946-), English mineralogist.
Physical Properties:
 Cleavage:
None
 Color:
black.
 Diaphaniety:
Opaque
 Habits:
Anhedral Grains - Granular minerals without the expression of crystal shapes, Microscopic Crystals - Crystals visible only with microscopes.,
 Hardness:
3-3.5 - Calcite-Copper Penny
 Luster:
Metallic
 Streak:
black
More details...