Ellisite

General Information:
 Chemical Formula:
Tl3AsS3
 Composition:
(Molecular Weight = 784.27 gm)
Thallium 78.18 % Tl
Arsenic 9.55 % As
Sulfur 12.27 % S 
 Empirical Formula:
Tl3AsS3
 IMA Status:
Approved IMA 1979
 Locality:
Carlin gold deposit, Eureka County, Nevada, USA.
 Name Origin:
Named for Albert J. Ellis (1929-), New Zealand geochemist.
Physical Properties:
 Cleavage:
[1011] Perfect, [1011] Perfect, [1011] Perfect
 Color:
dark gray.
 Density:
7.1
 Diaphaniety:
Opaque
 Habits:
Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals., ,
 Hardness:
2 - Gypsum
 Luster:
Metallic
 Streak:
pale brown
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