A lodestone is a naturally magnetized piece of the mineral magnetite. If a needle is rubbed on a lodestone or other magnet, the needle becomes magnetized. Only a small amount of the magnetite on the Earth is found magnetized as lodestone. Later compasses were made of iron needles, magnetized by striking them with a lodestone. With a more efficient compass magnetized by lodestone, the thermoremanence compass fell out of use. Lodestone is one of only a very few minerals that is found naturally magnetized. He battled the villain Lodestone, who attempted to remove his amulet. By the 12th century, the Chinese were known to use the lodestone compass for navigation. A boss called the Dark Elf resides in the Lodestone Cavern. He has since become the caregiver of Mento, Celsius, and Lodestone. He has appeared onstage at East West Players, Berkeley Repertory Theatre, and Lodestone Theatre Ensemble. The process by which lodestone is created has long been an open question in geology.