VS
Name
—
NaAl₃(SO₄)₂(OH)₆
Formula
—
Mineral Species
Entry type
—
Sulfates
Chemical class
—
Hexagonal
Crystal system
—
3.5–4
Mohs hardness
—
2.75–2.83
Specific gravity
—
White
Streak
—
Vitreous to pearly on {0001}
Luster
—
Distinct on {0001}; traces on {0112}
Cleavage
—
R-3m
Space group
—
Alunite-Alunite
Structural group
—
Nalu · Approved
IMA
—
1902
Named in
—
White; less commonly gray, yellow, green, brown; colorless in transmitted light
Typical colors
—
Na · Al · S · O · H
Elements
—