VS
Name
—
Ca₆Fe³⁺₂(SO₄)₂.₅[B(OH)₄](OH)₁₂·25H₂O
Formula
—
Mineral Species
Entry type
—
Sulfates
Chemical class
—
Hexagonal
Crystal system
—
2.5
Mohs hardness
—
1.847
Specific gravity
—
Pale yellow, greenish yellow, brownish orange if altered
Streak
—
Vitreous, slightly greasy on fracture surfaces
Luster
—
On {1010}, perfect
Cleavage
—
P31c
Space group
—
Ettringite
Structural group
—
Strm · Approved
IMA
—
1981
Named in
—
Bright yellow
Typical colors
—
Ca · Fe · S · O · B · H
Elements
—