General Information:
Chemical Formula:
Na2(Ta,Nb)4O11
Composition:
(Molecular Weight = 901.74 gm)
Sodium 5.10 % Na
Tantalum 70.23 % Ta
Niobium 5.15 % Nb
Oxygen 19.52 % O
Empirical Formula:
Na2Ta3.5Nb0.5O11
Environment:
Granitic pegmatites.
IMA Status:
Approved IMA
Locality:
Irtysh River area, eastern Kazakhstan.
Name Origin:
Named for the locality.
Physical Properties:
Cleavage:
None
Color:
colorless.
Density:
7.03
Diaphaniety:
Transparent
Habits:
Microscopic Crystals - Crystals visible only with microscopes., ,
Hardness:
7 - Quartz
Luster:
Adamantine
Streak:
white
More details...