Mineral - Bismutotantalite
Bismutotantalite
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
Bi(Ta,Nb)O₄
Unit Cell
a=4,98 b=11,85 c=5,68 Z=4
Physical Properties
Hardness
5 - 5.5
Streak
brownyellowyellow brown
Density
Very Heavy (>6)
Cleavage
Auf (010) gut, auf (101), (100), deutlich
Fracture
conchoidal,
uneven
Tenacity
Optical Properties
Color
blackbrowngray
Birefringence
0,038
Luster
Metallic,
Adamantine
Transparency
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
Space Group
Habit
coarse, massive, prismatic, tabular
Formation
Magmatic, in granitic pegmatites
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Bismutotantalite
Composition
Elements
Mass
Nb₂O₅
6,63
Ta₂O₅
40,12
Fe₂O₃
0,11
Bi₂O₃
52,26
Sb₂O₃
0,04
ZnO
0,33
MnO
0,12
Uganda
Groups and Members
Stibiotantalit-Gruppe