Chromite

Real mineral · uncommon · FeCr₂O₄

Iron chromium oxide and the sole commercial ore of chromium. Forms as a cumulate in layered ultramafic intrusions and in podiform deposits within oceanic crust. Essential for the production of stainless steel.

Identity

Formula
FeCr₂O₄
Chemical class
oxide
Mineral group
Magnetite, Spinel

Crystallography

Crystal system
cubic
Habits
massive, granular, octahedral
Fracture
conchoidal

Physical properties

Mohs hardness
5.5
Density
4.79 g/cm³
Luster
metallic, submetallic
Colors
black, brownish black
Streak
brown
Transparency
opaque

Geology

Origins
igneous
Host rocks
peridotite, dunite, serpentinite
Associated minerals
Olivine, pyroxene, Serpentine, Magnetite
Geography
Kazakhstan, South Africa, India, Zimbabwe, Finland

Classification

Rarity
uncommon
Gem quality
No

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