VS
Name
—
NaFe³⁺₃(Fe³⁺₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Hexagonal
Crystal system
—
7
Mohs hardness
—
3.26
Specific gravity
—
Brown
Streak
—
Resinous, more or less splendent
Luster
—
—
Cleavage
—
R3m
Space group
—
Tourmaline
Structural group
—
Pov · Approved
IMA
—
1979
Named in
—
Black
Typical colors
—
Na · Fe · Mg · Si · O · B · H
Elements
—