A
lodestone, or
loadstone, is a naturally
magnetized piece of the mineral
magnetite. They are naturally-occurring
magnets, which can attract
iron. The property of
magnetism was first discovered in antiquity through lodestones. Pieces of lodestone, suspended so they could turn, were the first
magnetic compasses, and their importance to early
navigation is indicated by the name
lodestone, which in
Middle English means 'course stone' or 'leading stone', from the now-obsolete meaning of
lode as ‘journey, way’.