General Information:
Chemical Formula:
(Na,K)ThSi11(O,F,OH)25·8(H2O)
Composition:
(Molecular Weight = 984.99 gm)
Potassium 0.99 % K
Sodium 1.75 % Na
Thorium 23.56 % Th
Silicon 31.36 % Si
Hydrogen 0.20 % H
Oxygen 32.49 % O
Fluorine 9.64 % F
Empirical Formula:
Na0.75K0.25ThSi11O18F5(OH)2
IMA Status:
Approved IMA
Locality:
DeMix quarry, Mt. St. Hilaire, Quebec, Canada.
Name Origin:
Named for its composition (Thorium, Na, Si).
Physical Properties:
Cleavage:
None
Color:
colorless or pale green.
Density:
2.62
Diaphaniety:
Transparent to Translucent
Habits:
Microscopic Crystals - Crystals visible only with microscopes., Anhedral Grains - Granular minerals without the expression of crystal shapes, Metamict - Mineral originally crystalline , now amorphous due to radiation damage.
Luminescence:
Fluorescent, Short UV=bright green, Long UV=bright green.
Luster:
Vitreous - Waxy
Streak:
white
More details...