What in the world is a Rare Earth Magnet?

I have seen a number of instructables that use "rare earth magnets".  What makes them so special?

excaza7 years ago
Rare earth magnets have much more powerful magnetic fields than the more common magnets such as those in toys or in your refrigerator magnet.  Because of their high strength, they're generally used in applications where you don't have very much space or weight allowance but still need a strong magnetic field.

Their most common use is in computer hard drives, they're also used in power tools and speakers.  They're very fun to play with and pretty inexpensive as well.

This should tell you what you need to know en.wikipedia.org/wiki/Rare-earth_magnet.
The "rare earth" elements, like Neodymium or Samarium give magnetic materials a particularly strong boost. Rather than saying they are neodymium-iron-boron magnets, or Samarium-cobalt, most people abbreviate it to "rare-earth magnets"