General Information:
Chemical Formula:
[ ]Na<0.5(Fe++,Al)3Al6Si6O18(BO3)3(OH)4
Composition:
(Molecular Weight = 1,208.15 gm)
Sodium 1.90 % Na
Aluminum 15.07 % Al
Iron 10.40 % Fe
Silicon 13.95 % Si
Boron 5.37 % B
Hydrogen 0.33 % H
Oxygen 52.97 % O
Empirical Formula:
NaFe3+2.25Al6.75Si6O18(BO3)3(OH)4
IMA Status:
Approved IMA
Physical Properties:
Cleavage:
None
Color:
bluish black.
Density:
3.17
Diaphaniety:
Translucent to Opaque
Hardness:
7 - Quartz
Luster:
Vitreous (Glassy)
Streak:
gray white
More details...