General Information:
Chemical Formula:
(K,Na)(Fe++,Mg)2(Al,Fe+++)3(Si,Al)12O30
Composition:
(Molecular Weight = 1,047.28 gm)
Potassium 2.80 % K
Sodium 0.55 % Na
Magnesium 1.16 % Mg
Aluminum 13.53 % Al
Iron 12.00 % Fe
Silicon 24.14 % Si
Oxygen 45.83 % O
Empirical Formula:
K0.75Na0.25Fe2+1.5Mg0.5Al2.25Fe3+0.75Si9Al3O30
Environment:
Acidic volcanic rocks.
Physical Properties:
Color:
blue, black, or light blue.
Density:
2.64
Diaphaniety:
Translucent
Hardness:
5-6 - Between Apatite and Orthoclase
Luster:
Vitreous (Glassy)
More details...