Mineral - Charoite
Charoite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
(K,Na)₅(Ca,Ba,Sr)₈[(OH,F)|Si₆O₁₆|(Si₆O₁₅)₂] · n H₂O
Unit Cell
Physical Properties
Hardness
5 - 6
Streak
white
Density
Normal (2-3,5)
Cleavage
Fracture
Tenacity
Optical Properties
Color
violet
Birefringence
0.009
Luster
Vitreous
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /m (11)
Habit
fibrous, massive
Formation
By metasomatic alteration of alkali-rich magmatic rocks in the presence of CO2-containing fluids
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Charoite