magnetite

noun

Etymology: From magnet + -ite, after German Magnetit.

1. A magnetic mineral, with the chemical formula Fe²⁺Fe3+2O₄, one of the primary ores of iron.

   “Appropriately enough, the commonest of these, a simple iron oxide, is called magnetite.”

2. Any instance of iron(II,III) oxide, regardless of whether it is a geologic mineral or a chemical result or product.