Laphamite

General Information:
 Chemical Formula:
As2(Se,S)3
 Composition:
(Molecular Weight = 351.55 gm)
Arsenic 42.62 % As
Selenium 50.54 % Se
Sulfur 6.84 % S 
 Empirical Formula:
As2Se2.25S0.75
 IMA Status:
Approved IMA 1985
Physical Properties:
 Cleavage:
[010] Perfect
 Color:
dark red.
 Density:
4.5
 Diaphaniety:
Translucent to Subopaque
 Hardness:
1-2 - Between Talc and Gypsum
 Luster:
Resinous
 Streak:
red orange
More details...