VS
Name
—
(Ce,Nd,La)(Fe³⁺,Ti,Fe²⁺,Al)₃O₂(Si₂O₇)₁₋ₓ₊ᵧ(AsO₃)₁₊ₓ₋ᵧ(OH)₃ₓ₋₃ᵧ
Formula
—
Mineral Species
Entry type
—
Silicates
Chemical class
—
Hexagonal
Crystal system
—
5
Mohs hardness
—
4.9
Specific gravity
—
Brownish black
Streak
—
Adamantine
Luster
—
{001}, poor
Cleavage
—
R3m
Space group
—
—
Structural group
—
Cvd-Ce · Approved
IMA
—
1986
Named in
—
Black; in transmitted light, yellowish, reddish brown to black
Typical colors
—
Ce · Nd · La · Fe · Ti · Al · O · Si · As · H
Elements
—