VS
Name
—
(Mg,Ti,Fe,Cr,Al)₂O(BO₃)
Formula
—
Mineral Species
Entry type
—
Borates
Chemical class
—
Orthorhombic
Crystal system
—
3.5–4
Mohs hardness
—
3.34–3.36
Specific gravity
—
Bluish black
Streak
—
Subvitreous to pearly, submetallic on cleavages, commonly dull if altered
Luster
—
On {100}, good
Cleavage
—
Pnam
Space group
—
Warwickite
Structural group
—
Wwk · Grandfathered
IMA
—
1838
Named in
—
Dark brown to black; deep yellow, pale brown, reddish brown in thin section
Typical colors
—
Mg · Ti · Fe · Cr · Al · O · B
Elements
—