Umbozerite

General Information:
 Chemical Formula:
Na3Sr4ThSi8(O,OH)24
 Composition:
(Molecular Weight = 1,266.20 gm)
Sodium 5.45 % Na
Strontium 27.68 % Sr
Thorium 18.33 % Th
Silicon 17.74 % Si
Hydrogen 0.48 % H 
Oxygen 30.33 % O 
 Empirical Formula:
Na3Sr4ThSi8O18(OH)6
 Environment:
In ussingite veinlets cutting alkalic rocks.
 IMA Status:
Approved IMA 1974
 Locality:
Umbozero (Lake Umba), Kola Peninsula, Russia.
 Name Origin:
Named for the locality.
Physical Properties:
 Cleavage:
None
 Color:
bottle green or greenish brown.
 Density:
3.6
 Habits:
Metamict - Mineral originally crystalline, now amorphous due to radiation damage., Pseudo Tetragonal - Crystals show a tetragonal shape.,
 Hardness:
5 - Apatite
 Luster:
Vitreous (Glassy)
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