Mineral description : Chromite

Small grains of chromite in serpentine from Horsmanaho, Finland.

Mineral class	Oxides : Chromite group.
Chemical formula	(Fe,Mg)Cr2O4
Crystal system	Cubic.
Habitus	Crystals octahedral, but very rare. Often as granular, nodular or massive.
Cleavage	None, uneven fracture.
Hardness	5.5
Density	4.5-4.8
Color	Black to brownish black.
Streak	Dark brown streak.
Luster	Metallic.
Description	Chromite is an important ore for chromium.
Occurance	Forms in ultrabasic and igneous rocks, often in serpentine rocks.
Associates	Serpentine, olivine.
Notes	Insoluble in acids, infusible in a flame and weakly magnetic.
Locations	A relatively rare mineral in Sweden, but some scattered occurances exists in the caledonides. Frostviken, Jämtland. As magmatic veins in olivine. Horsmanaho Finland. As small grains in a serpentine rock.

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