VS
Name
—
(Na,K,Ca)ₓMn₆(Si,Al)₁₀O₂₄(OH)₄·nH₂O (x = 1-2; n = 7-11)
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Monoclinic
Crystal system
—
3–4
Mohs hardness
—
2.76
Specific gravity
—
Light brown
Streak
—
Vitreous
Luster
—
Perfect on {001}
Cleavage
—
—
Space group
—
Clay
Structural group
—
Egg · Approved
IMA
—
1982
Named in
—
Dark to golden brown, red-brown
Typical colors
—
Na · K · Ca · Mn · Si · Al · O · H
Elements
—