Pyrite

The mineral pyrite, or iron pyrite, is an iron sulfide with the formula Fe S2. 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.