VS
Name
—
(Na,K)₃(Ta,Nb,Al)₁₁(O,OH)₃₁
Formula
—
Mineral Species
Entry type
—
Oxides & Hydroxides
Chemical class
—
Orthorhombic
Crystal system
—
3–4
Mohs hardness
—
5.5
Specific gravity
—
—
Streak
—
Silky
Luster
—
—
Cleavage
—
C222
Space group
—
—
Structural group
—
Rkm · Approved
IMA
—
1968
Named in
—
White to cream-white, may be yellowish due to iron staining; bluish gray to brownish in thin section
Typical colors
—
Na · K · Ta · Nb · Al · O · H
Elements
—