General Information:
Chemical Formula:
Bi(Ta,Nb)O4
Composition:
(Molecular Weight = 436.32 gm)
Tantalum 33.18 % Ta
Niobium 4.26 % Nb
Bismuth 47.90 % Bi
Oxygen 14.67 % O
Empirical Formula:
BiTa0.8Nb0.2O4
Environment:
In a pegmatite.
Locality:
Gamba Hill, Busiro Co., Uganda.
Name Origin:
Named for its composition (Bi, Ta).
Physical Properties:
Cleavage:
[010] Perfect, [101] Distinct
Color:
light brown or black.
Density:
8.51 - 8.84, Average = 8.67
Diaphaniety:
Subtranslucent to Opaque
Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Euhedral Crystals - Occurs as well-formed crystals showing good external form.,
Hardness:
5 - Apatite
Luster:
Adamantine - Metallic
Streak:
yellowish brown
More details...