General Information:
Chemical Formula:
Pb(Sb,As)2S4
Composition:
(Molecular Weight = 574.28 gm)
Antimony 40.28 % Sb
Arsenic 1.30 % As
Lead 36.08 % Pb
Sulfur 22.33 % S
Empirical Formula:
PbSb1.9As0.1S4
IMA Status:
Approved IMA 1967
Locality:
Madoc, Ontario, Canada.
Name Origin:
Named for Robert M. Thompson (1918-1967), Canadian Mineralogist: Thompson menas "son of Thomas," which is Aramaic for "twin."
Physical Properties:
Cleavage:
[100] Perfect
Color:
black.
Density:
5.26
Diaphaniety:
Opaque
Habits:
Microscopic Crystals - Crystals visible only with microscopes., ,
Hardness:
3.5 - Copper Penny
Luster:
Metallic
Streak:
brownish black
More details...