General Information:
Chemical Formula:
Na(CaNa)Fe++4(Al,Fe+++)Si7AlO22(OH)2
Composition:
(Molecular Weight = 953.22 gm)
Sodium 4.82 % Na
Calcium 4.20 % Ca
Aluminum 4.95 % Al
Iron 24.90 % Fe
Silicon 20.62 % Si
Hydrogen 0.21 % H
Oxygen 40.28 % O
Empirical Formula:
Na2CaFe2+4Al0.75Fe3+0.25Si7AlO22(OH)2
Environment:
Found in basic alkaline igneous rocks.
IMA Status:
Approved IMA 1997
Locality:
La Tabatiere, PQ, Canada and the Christiania region, Norway.
Name Origin:
Named from the Greek for "carrying down", in allusion to its volcanic origin.
Physical Properties:
Cleavage:
[110] Perfect, [010] Parting
Density:
3.2 - 3.5, Average = 3.35
Diaphaniety:
Translucent
Hardness:
5 - Apatite
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