| MadSci Network: Physics |
Hi, Joshua. In fact, some materials other than lodstone are "magnetic". In magnetism we classify the materials in some classes, depending upon the magnetic property called MAGNETIC SUSCETIBILITY, that is a value for a material that reflects the degree of magnetization that it can have. So, a material with suscetibility=0 could not be magnetized, and all other could be, in theory. In fact, all of the common materials present some suscetibility, but it is so tiny that the magnetic field that it generates is too much weak to be detected, unless you use some powerful magnetometer. And most of the materials present a magnetic field as they are exposed to a external magnetic field, and as this external field is nulled, they do not remain "magnetic". The materials that can "record" some magnetic information even when the external magnetic field goes to zero are called "magnetic" in the popular nomenclature. If you want to know what minerals/rocks can be classified as "magnetic" (in the popular nomenclature), I could list some: ilmenite, maghemite, hematite, pyrrhotite, chalcopyrite, and magnetite (lodstone). You can find some of them at http://www.smenet.org/opaque-ore/ Best regards Eder C. Molina Geophysicist Dept. of Geophysics Institute of Astronomy, Geophysics and Atmospheric Sciences - IAG UNIVERSITY OF SAO PAULO (USP) - BRASIL
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