Chemistry. a salt of chromium in the bivalent state.
Mineralogy. a cubic mineral, ferrous chromate, Fe 3 Cr 2 O 3 , usually with much of the ferrous iron and aluminum replaced by magnesium, and some of the chromium by ferric iron: the principal ore of chromium.
a brownish-black mineral consisting of a ferrous chromic oxide in cubic crystalline form, occurring principally in basic igneous rocks: the only commercial source of chromium and its compounds. Formula: FeCr2O4