VS
Name
—
NaMg₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Hexagonal
Crystal system
—
7.5
Mohs hardness
—
3.03–3.18
Specific gravity
—
Light brown, white
Streak
—
Vitreous to resinous
Luster
—
{1120}, {1011}, very poor
Cleavage
—
R3m
Space group
—
Tourmaline
Structural group
—
Drv · Grandfathered
IMA
—
1884
Named in
—
Brown, Black, Yellow
Typical colors
—
Na · Mg · Al · Si · O · B · H
Elements
—