General Information:
Chemical Formula:
Ba2CaMgAl2F14
Composition:
(Molecular Weight = 658.98 gm)
Barium 41.68 % Ba
Calcium 6.08 % Ca
Magnesium 3.69 % Mg
Aluminum 8.19 % Al
Fluorine 40.36 % F
Empirical Formula:
Ba2CaMgAl2F14
Environment:
Fluorite veins.
IMA Status:
Approved IMA 1967
Locality:
Upper Noiby River area, Yenisei region, Siberia, Russia.
Name Origin:
Named for Mikhail Antonovich Usov (1883-1939), Russian geologist.
Physical Properties:
Cleavage:
[???] Perfect
Color:
brown, dark brown, or yellowish brown.
Density:
4.18
Diaphaniety:
Translucent to Opaque
Habits:
Granular - Generally occurs as anhedral to subhedral crystals in matrix., Platy - Sheet forms (e.g. micas).,
Hardness:
3.5 - Copper Penny
Luster:
Vitreous - Greasy
Streak:
white
More details...