The mineral pyrite, or iron pyrite,'s an iron sulfide with the formula FeS2. This mineral's metallic luster and pale-to-normal, brass-yellow hue have earned it the nickname fool's gold due to its resemblance to gold. Pyrite's the most common of the sulfide minerals. The name pyrite's derived from the Greek πυρίτης (puritēs), “of fire” or "in fire”, from πύρ (pur), “fire”. This name's likely due to the sparks th… (More on Pyrite)