Pyrite is one of the best-known sulfide minerals and belongs to the sulfide mineral class. Chemically, it is iron disulfide (FeS₂). It is characterized by its metallic luster, brass-yellow color and frequently well-developed crystals, which commonly occur as cubes, pyritohedra or in more complex combinations.

The mineral forms in a wide variety of geological environments. Pyrite occurs in hydrothermal veins, sedimentary and metamorphic rocks, skarn deposits and numerous ore deposits. It can occur as an individual ore or gangue mineral, but also as an associated mineral together with quartz, calcite, galena, sphalerite, chalcopyrite or marcasite.

Some localities are especially well known for exceptionally well-developed pyrite crystals. These include Navajún in Spain, famous for its sharply formed cubic crystals, as well as various localities in Germany, Poland, Peru and other classic mining regions. Depending on the conditions of formation, pyrite crystals may occur individually on matrix, form dense aggregates or grow together with other sulfide and gangue minerals.

Pyrite is important both mineralogically and historically. Due to its high sulfur content, it was formerly used, among other purposes, for the production of sulfuric acid. For collectors, pyrite is especially attractive because of its distinctive crystal forms, strong metallic luster and the wide variety of mineral associations and localities in which it occurs.

The Mineralien Weltweit range includes pyrite specimens from various classic and lesser-known localities. Each collector specimen is documented with precise locality information, dimensions, weight and original photographs.