Iron-black, heavy, metallic oxide mineral , composed of iron and titanium oxide (FeTiO 3 ), which is the major source of titanium .
It is found disseminated or in veins in gabbro , diorite , or anorthosite , as in Quebec, New York state, and Norway. It also forms large masses, as in Iron Mountain, Wyoming, and in the Ilmen Mountains, Russia, from which it derives its name. Smaller quantities are present in copper-ore veins, pegmatites, black beach sands, and placer deposits.