General Information:
Chemical Formula:
KFe++2Al(Al2Si2)O10(F,OH)2
Composition:
(Molecular Weight = 484.90 gm)
Potassium 8.06 % K
Aluminum 16.69 % Al
Iron 23.03 % Fe
Silicon 11.58 % Si
Hydrogen 0.10 % H
Oxygen 34.64 % O
Fluorine 5.88 % F
Empirical Formula:
KFe2+2Al3Si2O10F1.5(OH)0.5
Physical Properties:
Cleavage:
[001] Perfect
Color:
blue green, dark brown, or black.
Density:
3
Diaphaniety:
Translucent
Hardness:
2.5-3 - Finger Nail-Calcite
Streak:
greenish gray
More details...