VS
Name
—
Na₂AlSi₃O₈(OH)
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Triclinic
Crystal system
—
6–7
Mohs hardness
—
2.46–2.49
Specific gravity
—
White
Streak
—
Slightly greasy to vitreous; slightly pearly on cleavage planes
Luster
—
Perfect on {110} and {110}
Cleavage
—
P-1
Space group
—
—
Structural group
—
Usg · Grandfathered
IMA
—
1915
Named in
—
Pale pink, lilac-blue, or dark violet-red, may be tarnished on the surface; colorless in thin section
Typical colors
—
Na · Al · Si · O · H
Elements
—