Great, open arch of pyrite with rock crystal

An open arch of pyrite with rock crystal from Peru. The inside of the cavity shows a two-mineral composition: golden pyrite cubes on one side, transparent quartz points on the other.

Pyrite (FeS₂) is an iron sulfide with a metallic golden luster. It crystallizes in cube, pentagonal dodecahedron, or octahedron forms. Peruvian deposits in Huanzala yield pyrite of the highest crystallographic quality in combination with quartz mineralizations.

The arch shape documents a special deposit geometry. In a cavity-arch structure, the two minerals crystallized synchronously, separated by the side of the cavity wall.

Pyrite is hard (Mohs 6.5) and stable, but can oxidize under unfavorable storage conditions. Dry, dark storage is the professional preservation method.

A Peruvian collector's item with two-mineral genesis and unusual arch geometry.