General Information:
Chemical Formula:
[ ]Na2(Mg3Fe++2)Si8O22(OH)2
Composition:
(Molecular Weight = 841.27 gm)
Sodium 5.47 % Na
Magnesium 8.67 % Mg
Iron 13.28 % Fe
Silicon 26.71 % Si
Hydrogen 0.24 % H
Oxygen 45.64 % O
Empirical Formula:
Na2Mg3Fe3+2(Si8O22)(OH)2
IMA Status:
Approved IMA 1978
Physical Properties:
Cleavage:
[110] Perfect
Color:
light blue, dark blue, black, or black blue.
Density:
3.19
Diaphaniety:
Translucent to Subopaque
Hardness:
5 - Apatite
Luster:
Vitreous - Silky
Streak:
blue gray
More details...