Mineral - Holtite
Holtite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
(Ta₀,6 □0,4)Al₆BSi₃O₁₈(O,OH)₂,25
Unit Cell
Physical Properties
Hardness
1 - 10
Streak
brownyellowyellow brown
Density
Cleavage
Fracture
Tenacity
Optical Properties
Color
whitebrownpinkviolet
Birefringence
Luster
Vitreous,
Resinous
Transparency
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
Space Group
Habit
acicular, prismatic, prismatic, tabular
Formation
Aus Tantalit in Pegmatiten, alluvial
Paragenesis
Twinning
Rarity
Synonyms
Holtite