General Information:
Chemical Formula:
(K,Na)Ca2(Mg,Fe++)5Si8O22(OH,F)2
Composition:
(Molecular Weight = 906.49 gm)
Potassium 2.16 % K
Sodium 1.27 % Na
Calcium 8.84 % Ca
Magnesium 8.04 % Mg
Iron 12.32 % Fe
Silicon 24.79 % Si
Hydrogen 0.22 % H
Oxygen 42.36 % O
Empirical Formula:
K0.5Na0.5Ca2Mg3Fe2+2(Si8O22)(OH)2
Environment:
With calcite in a metasomatic or skarn-type deposit.
IMA Status:
Approved IMA (Dana # Added)
Locality:
Pargas, Turku-Pori, Finland.
Name Origin:
Named after its containing potassium and the locality.
Physical Properties:
Cleavage:
[110] Perfect
Color:
black.
Density:
3.25
Diaphaniety:
Translucent to opaque
Habits:
Intergrown Crystals - Occurs as intergrown crystalline aggregates, Aggregates - Made of numerous individual crystals or clusters.,
Hardness:
6-6.5 - Orthoclase-Pyrite
Luminescence:
Non-fluorescent.
Luster:
Vitreous (Glassy)
Streak:
brownish green
More details...