Here's why:
* Fool's gold is not a magnetic material. It is composed of iron sulfide (FeS2), which is not attracted to magnets.
* True gold is also not magnetic. While gold can be alloyed with other metals to create magnetic materials, pure gold is not magnetic.
So, if something sticks to a magnet, it's likely real gold, but it's best to get it tested by a professional to confirm its authenticity.