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Chromite (Photo) [abbr. Chr ]

Year of discovery: 1845 (Bastide de la Carrade, France), 1877 (Japan)

Locality list: 521 localities of chromite

• FeCr₂O₄
• (Fe,Mg)(Cr,Al)₂O₄
• [Fe²⁺][Cr³⁺₂][O₄]^8-

• Class: Spinel subgroup < Oxyspinel group < Spinel supergroup
• Class: Oxide
• Insoluble in: HCl
• Magnetism: Paramagnetic (Weak)

• Fe => Mg: Magnesiochromite (Series)
• Fe => Mn: Manganochromite
• Fe => Co: Cochromite
• Fe => Zn: Zincochromite

• Cr => Al: Hercynite (Series)
• Cr => Fe: Magnetite (Series)
• Cr => V: Coulsonite
• Cr => (Fe,Ti,[]): Titanomaghemite

• Color: Iron black
• Streak: Dark brown
• Luster: Metallic
• Diaphaneity: Opaque

• Habit: Octahedral

• Cleavage: No, Parting on {111} (4 planes)
• Hardness: 5.5
• Density: 4.7

• System: Cubic
• Group: m3m, Fd3m
• Lattice: a=8.3

Etymology: Chrome (color) in Greek