VS
Name
—
(MgAl₃)(MgAl)Al₂O₂(SiO₄)₄(OH)₂
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Monoclinic
Crystal system
—
6
Mohs hardness
—
3.39
Specific gravity
—
—
Streak
—
Vitreous
Luster
—
Partings [001], good and {100}, poor
Cleavage
—
P2_1/m
Space group
—
—
Structural group
—
Yod · Approved
IMA
—
1959
Named in
—
Deep purple, emerald-green; in transmitted light, deep blue to olive-green, green to yellow
Typical colors
—
Mg · Al · O · Si · H
Elements
—