VS
Name
—
(Fe²⁺₀.₅Fe³⁺₀.₅)₂Fe³⁺₃(PO₄)₃(OH)₅
Formula
—
Mineral Species
Entry type
—
Phosphates
Chemical class
—
Orthorhombic
Crystal system
—
3.5–4.5
Mohs hardness
—
3.45
Specific gravity
—
—
Streak
—
Vitreous to dull
Luster
—
{100}, excellent; {010}, good; {001}, fair
Cleavage
—
Bbmm
Space group
—
Rockbridgeite
Structural group
—
Rkb · Grandfathered
IMA
—
1949
Named in
—
Dark green, olive-green, greenish black, black, commonly color-banded; may be bronze-brown
Typical colors
—
Fe · P · O · H
Elements
—