General Information:
Chemical Formula:
Fe+++5V++++3V+++++12O39·8.5(H2O)
Composition:
(Molecular Weight = 1,820.46 gm)
Vanadium 41.97 % V
Iron 15.34 % Fe
Hydrogen 0.94 % H
Oxygen 41.75 % O
Empirical Formula:
Fe3+5V4+3V5+12O39·8.5(H2O)
Environment:
Black shales.
IMA Status:
Approved IMA
Locality:
Northwestern Karatau, Kazakhstan.
Name Origin:
Named for the locality.
Physical Properties:
Cleavage:
[001] Perfect
Color:
black.
Density:
3.4 - 3.6, Average = 3.5
Diaphaniety:
Opaque
Habits:
Microscopic Crystals - Crystals visible only with microscopes., ,
Hardness:
2.5 - Finger Nail
Luster:
Subadamantine
Streak:
brownish black
More details...