VS
Name
—
(NaCa)(Mg₄Al)Si₈O₂₂(OH)₂
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Monoclinic
Crystal system
—
5–6
Mohs hardness
—
2.97–3.17
Specific gravity
—
—
Streak
—
[Vitreous.]
Luster
—
[Perfect on {110}, intersecting at ~56° and ~124°; partings on {100}, {001}.]
Cleavage
—
C2/m
Space group
—
Amphibole
Structural group
—
Wnc · Approved
IMA
—
1906
Named in
—
Colorless, cobalt blue to bluish violet; colorless to pale blue in thin section
Typical colors
—
Na · Ca · Mg · Al · Si · O · H
Elements
—