5311581 Woodcut showing a Lodestone on board, floating in a bowl of water. It was possible to demonstrate in this way the fact that however placed it would come to rest with a north/south orientation (star-shaped objects are pointers). From Athanasius Kircher Magnes sive de Arte Magnetica, Cologne, 1643. A lodestone is a naturally magnetized piece of the mineral magnetite. They are naturally occurring magnets, which can attract iron. Pieces of lodestone, suspended so they could turn, were the first magnetic compasses; Universal History Archive/UIG.