Most magnetic bodies must be made magnetic by using some outside influence such as electricity. There are, however, certain metals which naturally possess the ability to attract other metals. These natural magnets, called lodestones, are composed of an iron oxide called magnetite.
Generally, magnetite is found in the unmagnetized state. Even in the unmagnetized state it is still much more strongly attracted by other magnets than most metals. Another common name for this iron ore is magnetic iron. The chemical composition of magnetite is Fe3O4. It has a specific gravity of 5.18 and its hardness is six on the Mohs hardness scale.
