General Information:
Chemical Formula:
(U,Ca)2(Ta,Nb)2O6(OH)
Composition:
(Molecular Weight = 695.81 gm)
Calcium 6.91 % Ca
Uranium 27.37 % U
Tantalum 46.81 % Ta
Niobium 2.67 % Nb
Hydrogen 0.14 % H
Oxygen 16.10 % O
Empirical Formula:
U0.8Ca1.2Ta1.8Nb0.2O6(OH)
IMA Status:
Approved IMA
Locality:
Fazenda Posse, Brejauba district, Municiop de Conceicao de Serro, Minas Gerias, Brazil.
Name Origin:
Named for uranium and as a member of the microlite group.
Physical Properties:
Cleavage:
None
Color:
greenish brown, yellow brown, or black.
Density:
5.75 - 5.88, Average = 5.81
Diaphaniety:
Transparent to Opaque
Habits:
Octahedral Crystals - Occurs as octahedral shaped crystals., ,
Hardness:
5.5 - Knife Blade
Luminescence:
Highly Radioactive.
Luster:
Greasy (Oily)
Streak:
yellow
More details...