General Information:
Chemical Formula:
(Fe++,Mg)Al2Si2O6(OH)4
Composition:
(Molecular Weight = 322.12 gm)
Magnesium 1.89 % Mg
Aluminum 16.75 % Al
Iron 13.00 % Fe
Silicon 17.44 % Si
Hydrogen 1.25 % H
Oxygen 49.67 % O
Empirical Formula:
Fe2+0.75Mg0.25Al2Si2O6(OH)4
Physical Properties:
Cleavage:
[010] Perfect, [110] Indistinct
Color:
gray green or dark green.
Density:
3.04
Diaphaniety:
Translucent
Hardness:
5.5 - Knife Blade
Luster:
Silky
Streak:
greenish white
More details...