General Information:
Chemical Formula:
NaFe+++Si2O6
Composition:
(Molecular Weight = 231.00 gm)
Sodium 9.95 % Na
Iron 24.18 % Fe
Silicon 24.32 % Si
Oxygen 41.56 % O
Empirical Formula:
NaFe3+(Si2O6)
Environment:
Sodium rich igneous nepheline syenites.
IMA Status:
Approved IMA 1987
Locality:
TL: Norway, Buskerud, Kongsberg. Magnet Cove, Hot Spring County, Arkansas.
Name Origin:
Named after the Teutonic god of the sea. Acmite is from the Greek "point" in allusion to the pointed crystals.
Physical Properties:
Cleavage:
[???] Distinct, [???] Distinct
Color:
green, greenish black, reddish brown, or black.
Density:
3.5 - 3.54, Average = 3.52
Diaphaniety:
Subtransparent to translucent to opaque
Habits:
Acicular - Occurs as needle-like crystals., ,
Hardness:
6-6.5 - Orthoclase-Pyrite
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Resinous
Streak:
yellowish gray
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