sesquioxides thiolates FeS Fe3O4 teppan dithionite pisolites Carbonyl ferric aluminothermic oxides FeS2 nitrosyl inosilicate oxyhydroxide Fe2 NiFe ammoniac 2Fe ferrous oregrounds Nb2O5 manganese nonheme FeO Transferrin Ferric chelate cyclobutadiene Ferrous chelated pizzelle Fe3