MAGNETITE
magnetite, magnetic iron-ore
(noun) an oxide of iron that is strongly attracted by magnets
Source: WordNet® 3.1
Etymology
Noun
magnetite (plural magnetites)
(mineral) A magnetic mineral, Fe3O4, one of the primary ores of iron. It has also been called lodestone.
Source: Wiktionary
Mag"net*ite, n. (Min.)
Definition: An oxide of iron (Fe3O4) occurring in isometric crystals, also
massive, of a black color and metallic luster. It is readily
attracted by a magnet and sometimes possesses polarity, being then
called loadstone. It is an important iron ore. Called also magnetic
iron.
Source: Webster’s Unabridged Dictionary 1913 Edition