Who invented magnets?
The first magnets were not invented, but rather were found from a naturally occurring mineral called magnetite. Traditionally, the ancient Greeks were the discoverers of magnetite. There is a story about a shepherd named Magnes whose shoe nails stuck to a rock containing magnetite. There is an alternate story about a region of Macedonia called Magnesia as the starting point. I remember being taught that the Greeks discovered naturally occurring magnets of magnetite in Turkey. Magnetite occurs all over the world, but there are especially large deposits in Scandinavia. The Vikings invented the first practical magnetic compass and used it extensively in their travels to colonize or in war. This enabled them to cross oceans to reach the new world and to invade England at will, even in the dense fog. The Vikings kept the existence of the magnetic compass a secret. The Chinese also invented the magnetic compass, probably earlier than the Vikings. After commercial trade with China was started by the Italians, especially after Marco Polo's trip, the magnetic compass was introduced to the rest of Europe. This made possible the exploration of the oceans by the Europeans, although the Norsemen had a monopoly for almost 500 years and thus a big head start. Today all ships large and small use magnetic compasses to navigate.
The mineral magnetite is an iron oxide that is easily magnetized when it forms. Magnetite is also known as Lodestone.
Paul Brindza, Experimental Hall A Design Leader (Other answers by Paul Brindza)