VS
Name
—
Mn²⁺Al₂O(SiO₄)(OH)₂
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Monoclinic
Crystal system
—
6–7
Mohs hardness
—
3.52
Specific gravity
—
Greenish, grayish
Streak
—
Vitreous to nearly adamantine on cleavages
Luster
—
{001}, perfect; {110}, likely
Cleavage
—
—
Space group
—
Chloritoid
Structural group
—
Otr · Grandfathered
IMA
—
1842
Named in
—
Pistachio-green, greenish to dark gray; in transmitted light, gray-green
Typical colors
—
Mn · Al · O · Si · H
Elements
—