Mineral - Tantalite-(Mn)
Tantalite-(Mn)
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
Mn²⁺Ta₂O₆
Unit Cell
a=14,44 b=5,77 c=5,09 Z=4
Physical Properties
Hardness
6
Streak
blackred
Density
Very Heavy (>6)
Cleavage
Auf (100) deutlich, auf(010) weniger deutlich
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
blackbrownred
Birefringence
0,200
Luster
Vitreous,
Metallic
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
Space Group
Habit
blocky, lath-shaped, prismatic, tabular
Formation
In granitischen Pegmatiten
Paragenesis
Twinning
Kontaktzwillinge auf (021) und (023), pseudohexagonale Rotationszwillinge
Rarity
Rather rare
Synonyms
Tantalite-(Mn)
Composition
Elements
Mass
Nb₂O₅
0,29
Ta₂O₅
85,90
SnO₂
0,03
FeO
0,04
MnO
13,80
CaO
0,16
Mosambik
Groups and Members
Columbit-Supergruppe
Columbit-Gruppe