The anhydrous iron oxide Fe2O3 which has a defect spinel structure with a hematite stoichiometry. It also exists in the Fe2O3 polymorph. Maghemite has a cation vacancy, so its structure is more accurately written as Fe3(Fe5-O12. It is highly ferromagnetic, and does not lose its magnetism easily upon contact. However, it is weak enough to be fairly easily realigned. It is the coating used on floppy disks and cassettes. It forms when iron minerals rust.
Fe2O3 which has a defect spinel structure with a hematite stoichiometry. It also exists in the 
Fe2O3 polymorph. Maghemite has a cation vacancy, so its structure is more accurately written as Fe3(Fe5-O12. It is highly ferromagnetic, and does not lose its magnetism easily upon contact. However, it is weak enough to be fairly easily realigned. It is the coating used on floppy disks and cassettes. It forms when iron minerals rust.