General Information:
Chemical Formula:
([ ],Fe,Mg)(Mg,Al,Fe)5Al4Si2(Si,Al)2(B,Si,Al)(O,OH,F)22
Composition:
(Molecular Weight = 753.84 gm)
Magnesium 9.99 % Mg
Aluminum 21.83 % Al
Iron 5.93 % Fe
Silicon 14.16 % Si
Boron 0.86 % B
Hydrogen 0.53 % H
Oxygen 46.69 % O
Empirical Formula:
Fe2+0.3Mg0.1Mg3Al1.5Fe3+0.5Al4.6Si3.8B0.6O18(OH)4
IMA Status:
Approved IMA
Physical Properties:
Cleavage:
[110] Perfect
Color:
yellow brown, green brown, or brown green.
Density:
3.341 - 3.345, Average = 3.34
Diaphaniety:
Transparent to Translucent
Hardness:
6.5-7 - Pyrite-Quartz
Luster:
Vitreous (Glassy)
Streak:
white
More details...