Mineral Name
Chemical Formula
KAl2(AlSi3O10)(OH)2
Preview
Color
dark brown, greenish-brown, blackish-brown, yellow, white
Class
Article
Luster
vitreous - pearly
Diaphaneity
transparent to translucent to opaque
Hardness
2.5-3
Cleavage
1 direction: {001} perfect
Fracture
uneven, flat surfaces
Density
2.8-3.4
Crystal Shape
rarely in tabular or short prismatic crystals with prominent {001} and pseudohexagonal outline.
Crystal System
Monoclinic
COinS
