General Information:
Chemical Formula:
KFe++3AlSi3O10(OH,F)2
Composition:
(Molecular Weight = 512.88 gm)
Potassium 7.62 % K
Aluminum 5.26 % Al
Iron 32.67 % Fe
Silicon 16.43 % Si
Hydrogen 0.29 % H
Oxygen 35.87 % O
Fluorine 1.85 % F
Empirical Formula:
KFe2+3AlSi3O10(OH)1.5F0.5
Physical Properties:
Cleavage:
[???] Perfect
Color:
reddish brown or black.
Density:
3.17
Diaphaniety:
Transparent to Subopaque
Hardness:
2.5-3 - Finger Nail-Calcite
Luster:
Sub Metallic
Streak:
brownish white
More details...