Valleriite

General Information:
 Chemical Formula:
4(Fe,Cu)S·3(Mg,Al)(OH)2
Physical Properties:
 Cleavage:
[???] Perfect
 Color:
bronze or gray.
 Density:
3.09 - 3.14, Average = 3.11
 Diaphaniety:
Opaque
 Hardness:
1-1.5 - Talc or a little harder
 Luster:
Metallic
More details...