Adamantite

Adamantite may refer to:
 * The recurring item
 * The armor from Final Fantasy X.
 * The accessory from Final Fantasy X-2.
 * The accessory from Dissidia Final Fantasy.
 * The accessory from Dissidia 012 Final Fantasy.

Etymology
and similar words are used to refer to any especially hard substance, whether composed of diamond, some other gemstone, or some type of metal.