VS
Name
—
NaFe²⁺₃Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH)
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Hexagonal
Crystal system
—
7–7.5
Mohs hardness
—
3.18–3.22
Specific gravity
—
White
Streak
—
Vitreous to resinous
Luster
—
{1120}, {1011}, very poor
Cleavage
—
R3m
Space group
—
Tourmaline
Structural group
—
Srl · Approved
IMA
—
1562
Named in
—
Black
Typical colors
—
Na · Fe · Al · Si · O · B · H
Elements
—