VS
Name
—
Na(NaCa)(Mg₄Al)(Si₇Al)O₂₂(OH)₂
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Monoclinic
Crystal system
—
5–6
Mohs hardness
—
3.2–3.5
Specific gravity
—
—
Streak
—
Vitreous
Luster
—
Perfect on {110}, intersecting at ~56° and ~124°; parting on {010}
Cleavage
—
C2/m
Space group
—
Amphibole
Structural group
—
Ktp · Approved
IMA
—
1894
Named in
—
Black, dark green-black, bluish black; reddish yellow, bluish green in thin section
Typical colors
—
Na · Ca · Mg · Al · Si · O · H
Elements
—