Pyrite, also known as "fools gold," is a mineral composed of iron and sulfur. It has been used for various purposes throughout history, including:

• Production of sulfuric acid: Pyrite used to be an important ore for the production of sulfur and sulfuric acid. Today, most sulfur is obtained as a byproduct of oil and gas processing, but some sulfur continues to be produced from pyrite as a byproduct of gold production.

• Polishing and ornamental stone: Pyrite was polished by Native Americans in early times and used as mirrors. It is also used as an ornamental stone and collectors item.

• Gemstone: Pyrite is occasionally used as a gemstone. It can be fashioned into beads, cut into cabochons, faceted, and carved into shapes.

• Protection and spiritual uses: Pyrite is believed to have protective properties and is used in spiritual practices to attract wealth, abundance, and success. It is also thought to strengthen the solar plexus chakra and protect the aura.

• Oil exploration: Pyrite can precipitate in reducing sulfate-rich environments created by the migration of crude oil into the rock system in deeper layers. Its presence can indicate that chemically reducing conditions prevailed at some time in the past, allowing organic carbon to be preserved.

Overall, the uses of pyrite have declined over time, but it still has some industrial and spiritual applications.