The First Discovery of Magnetism: Lodestone
If you are a magnet enthusiast or geology buff, you may have heard of a magnetic stone known as lodestone. The properties and origins of this magnetic material make it quite an interesting study. Lodestone has been linked as far back as 600 BC and is often cited in history as the first indication of magnetism, leading to further magnetic discoveries like the early compass in China.
History of Lodestone
Lodestone is a naturally occurring type of mineral magnetite, which is composed of iron oxide. This type of magnetite separates itself from others because it has a north and south polarity configuration. So, instead of being attracted by a magnet, it acts as one. Since they are found near the Earth’s surface, one prominent theory about how they were created points to lightning strikes.Lodestone Today
Although lodestone is one of only two natural magnets, modern day magnets are much stronger. It is because of this fact that you won’t see it being used in today’s magnetic gadgets and other accessories. Today, there are about four primary materials of which permanent magnets are made and those are:- Neodymium-boron-iron (Neodymium, NdFeB)
- Samarium-Cobalt (SmCo)
- Aluminum-Nickel-Cobalt (Alnico)
- Ceramic/Ferrite