The mineral or iron pyrite, also known as fool's gold, is an iron sulfide Fe 2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral.
Pyrite's metallic luster and pale brass-yellow hue, hence the well-known nickname of fool's gold. The color has also led to the nicknames brass, brazzle, and Brazil, primarily used to refer to pyrite found in coal
The name pyrite is derived from the Greek πυρίτης λίθος (pyritēs lithos), "stone or mineral which strikes 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, c. 1550, the term had become a generic term for all of the sulfide minerals
Pyrite is usually found associated with other sulfides or oxides in quartz , sedimentary rock, as well as in coal beds and as a replacement mineral in fossils , but has also been identified in the sclerites of scaly-foot gastropods Despite being nicknamed fool's gold, pyrite is sometimes found in association with small quantities of gold. A substantial proportion of the gold is "invisible gold" incorporated into the pyrite (see Carlin-type gold deposit). It has been suggested that the presence of both gold and arsenic is a case of coupled substitution but as of 1997 the chemical state of the gold remained controversial.