VS
Name
—
(Na,K)ₓV⁴⁺ₓV⁵⁺₆₋ₓO₁₅ (0.5<x<0.9)
Formula
—
Mineral Species
Entry type
—
Oxides & Hydroxides
Chemical class
—
Monoclinic
Crystal system
—
—
Mohs hardness
—
3.5
Specific gravity
—
Dark gray-black
Streak
—
Submetallic
Luster
—
{100}, perfect; {010}, fair
Cleavage
—
C2/m
Space group
—
—
Structural group
—
Bnm · Approved
IMA
—
1980
Named in
—
Black; light brown on thin edges in transmitted light
Typical colors
—
Na · K · V · O
Elements
—