Pyrite (iron sulfide), with its brassy-yellow color and bright metallic luster, is the one-and-only Fools Gold! Add to its color and luster an amazing variety of striking crystal forms, and it’s understandable why it’s one of the most collectable minerals. The famous perfect cubes from Spain are especially treasured among collectors. And I have amassed hours at shows convincing onlookers that these cubes are, in fact, natural. Often in vain. This amazing mineral is associated with numerous contrasting minerals, including Quartz, Calcite, Fluorite, Barite, Dolomite and Rhodochrosite.
The crystal system for Pyrite is isometric, commonly forming cubic, octahedral and pyritohedral crystals, and various combinations of these forms, including perfect cubes and fascinating penetration twins. Other forms include inter-grown, granular, radiating, massive, druzy, encrusting, nodular, striated, concretions, aggregates of small crystals and flattened nodular (Pyrite Suns).
Pyrite is an extremely common mineral, and quality specimens occur in numerous localities throughout the world. Notable locations include Italy, Peru, Spain, Tanzania and the USA (Utah, Colorado, Illinois).