Iron(II,III) oxide, 99.99% is the chemical compound with formula Fe3O4. It occurs in nature as the mineral magnetite.
I 0381 (OTTO) Iron(II,III) oxide, 99.99% Cas 1317-61-9 - used as a contrast-agent in MRI scanning and as a pigment in magnetic applications, polishing compounds, cosmetics, medicines, polymers, rubber, fillers, building, construction, appliances and magnetic inks.