1.NounA magnetic mineral, with the chemical formula .mw-parser-output .template-chem2-su{display:inline-block;font-size:80%;line-height:1;vertical-align:-0.35em}.mw-parser-output .template-chem2-su>span{display:block;text-align:left}.mw-parser-output sub.template-chem2-sub{font-size:80%;vertical-align:-0.35em}.mw-parser-output sup.template-chem2-sup{font-size:80%;vertical-align:0.65em}FeFe3+2O4, one of the primary ores of iron.
2.NounAny instance of iron(II,III) oxide, regardless of whether it is a geologic mineral or a chemical result or product.