VS
Name
—
Na₂(Fe²⁺₃Al₂)Si₈O₂₂(OH)₂
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
—
Crystal system
—
6
Mohs hardness
—
3.18–3.34
Specific gravity
—
—
Streak
—
[Vitreous.]
Luster
—
[Perfect on {110}, intersecting at ~58° and ~122°.]
Cleavage
—
—
Space group
—
Amphibole
Structural group
—
Fgln · Approved
IMA
—
1957
Named in
—
Blue to bluish gray
Typical colors
—
Na · Fe · Al · Si · O · H
Elements
—