The mineral pyrite, or iron pyrite, is an iron sulfide with the formula FeS2. This mineral's metallic luster and pale brass-yellow hue have earned it the nickname fool's gold because of its superficial resemblance to gold. The color has also led to the nicknames brass, brazzle and Brazil, primarily used to refer to pyrite found in coal. Pyrite is the most common of the sulfide minerals. The name pyrite is derived from the Greek, ''of fire'' or ''in fire'', in turn from (pur), ''fire''. In ancient Roman times, this name was applied to several types of stone that would create sparks when struck against steel; Pliny the Elder described one of them as being brassy, almost certainly a reference to what we now call pyrite. By Georgius Agricola's time, the term had become a...'
Contributions by Vsmith, Smokefoot, and DanielCD.