Pyrite

Pyrite, commonly known as “fool’s gold,” is an iron sulfide mineral with a distinctive metallic luster and pale brass-yellow color. It is the most widespread sulfide mineral on Earth and forms in a wide variety of geological environments — from sedimentary deposits to hydrothermal veins.

Pyrite crystallizes in the cubic system and often forms well-developed cubes, pyritohedra, or octahedra. The cubic crystals from Navajún, La Rioja, Spain are especially prized by collectors for their sharp, nearly perfect cube faces.

This specimen shows characteristic cubic habit with striated faces and a bright metallic luster.