Which mineral is commonly known as "fools gold"?

Explanation:

Pyrite is the mineral commonly known as "fools gold." It has a metallic luster and brassy yellow color, which can often fool people into thinking it is real gold. However, pyrite is iron sulfide and does not contain any gold. It is often found in association with gold deposits, hence its nickname "fools gold."

While galena, topaz, and talc are all minerals, they are not commonly referred to as "fools gold." Galena is a lead sulfide mineral, topaz is a silicate mineral, and talc is a hydrated magnesium silicate mineral.