Market Brief Chromite is the commercial name for iron chromium oxide FeCr 2 O 4 a mineral containing chromium a transition metal with multiple oxidation states and iron oxide In its purest form chromite comprises chromium Cr 2 O 3 at 68 and iron oxide FeO at 32 Chromite occurs exclusively in ultramafic rocks such as dunite peridotite pyroxenite and serpentinite