Mineral - Charlesite
Charlesite
Chemical Properties
Mineral Class
Sulphates
Toxicity
none
Formula
Ca₆(Al,Si)₂(SO₄)₂B(OH)₄(OH,O)₁₂·26H₂O
Unit Cell
Physical Properties
Hardness
2.5
Streak
white
Density
Light (<2)
Cleavage
Fracture
Tenacity
Brittle
Optical Properties
Color
whiteyellowgreencolorless
Birefringence
0.017
Luster
Vitreous,
Waxy
Transparency
translucent,
transparent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Point Group
ditrigonal-pyramidal - 3m
Space Group
P3c1 (158)
Habit
blocky, prismatic, Rhombohedron, Scalenohedron
Formation
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Charlesite
Groups and Members
Ettringite-Group