How old usually is pyrite?

Pyrite, also known as "fool's gold," is typically formed in a variety of geological environments and can be found in rocks that are millions to billions of years old. It commonly occurs in sedimentary, metamorphic, and igneous rocks, with some deposits dating back to the Archean eon, around 3.5 billion years ago. Thus, the age of pyrite can vary widely depending on its specific geological context.