Fool’s gold is a common plot device in old comedies – a hapless, wannabe prospector thinks he has found the mother load, but someone eventually tells him all he has is a pile of fool’s gold. While fool’s gold may have little value, it still has its uses.
Fool’s gold is actually a mineral known as pyrite. Pyrite is an iron sulfide with a roughly 50/50 construction of iron and sulfur. Because of its lustrous shine and yellow color, it can easily be mistaken for gold if it’s not carefully examined. Luckily, it doesn’t take an expert to tell the difference. While pyrite is yellow, it’s much paler than gold – taking on a more brassy, sallow hue. In addition, pyrite weighs much less and is harder and more brittle than gold.
Since pyrite is an extremely common mineral found all over the world, it isn’t worth very much. However, it does have unique properties. Pyrite is used in jewelry, but it’s too brittle to be used on its own. Instead, it’s mixed with silver to give the metal a unique glimmer. The silver also helps stabilize the pyrite, which can oxidize easily. If left in a damp environment for even a short amount of time, it will break down quickly. However, that’s just another useful trait of the mineral. Because of its commonality and oxidative properties, pyrite is a cheap source of sulfuric acid and sulfuric gases – which are used in many industrial applications.
If you find any pyrite while hunting for gold, don’t give up hope. It’s not a common occurrence, but pyrite has been known to form in and around gold ore – so there may be some nearby! If not, you at least have one of nature’s most beautiful minerals (just don’t get it wet).