General Information:
Chemical Formula:
UO2
Composition:
(Molecular Weight = 270.03 gm)
Uranium 88.15 % U
Oxygen 11.85 % O
Empirical Formula:
UO2
Environment:
Granite and syenite pegmatites. Colloform crusts in high temperature hydrothermal veins. In quartz-pebble conglomerates.
IMA Status:
Approved IMA 1962
Locality:
Southern parts of the Canadian Precambrian Shield, Bancroft, Ontario. New Hampshire, USA. Transvaal gold-bearing conglomerates.
Name Origin:
From its elemental composition containing uranium.
Physical Properties:
Cleavage:
[???] Good
Color:
brownish black, gray, grayish black, or black.
Density:
6.5 - 10.95, Average = 8.72
Diaphaniety:
Nearly opaque
Habits:
Crystalline - Coarse - Occurs as well-formed coarse sized crystals., Botryoidal - "Grape-like" rounded forms (e.g.. malachite)., Dendritic - Branching "tree-like" growths of great com plexity (e.g. pyrolusite).
Hardness:
5-6 - Between Apatite and Orthoclase
Luminescence:
Non-fluorescent.
Luster:
Sub Metallic
Streak:
brownish black
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