Great pyrite with many rock crystal points and pyrite cubes

A pyrite specimen accompanied by rock crystal: brass-golden pyrite cubes and clear rock crystal points grow together from the matrix, a classic example of co-crystallization in a hydrothermal vein.

Pyrite is iron sulfide (FeS₂), rock crystal is pure silicon dioxide (SiO₂). Both minerals can grow in parallel in the same deposit if the hydrothermal solutions are rich in both sulfur and silica.

The cubic form of pyrite arises from its cubic crystal system; the hexagonal-prismatic form of rock crystal points from the trigonal quartz system. Both growth habits are characteristic of undisturbed crystallization.

Such double-mineral specimens with clear representatives of both growth habits are particularly sought after by collectors: they show the multifaceted nature of a deposit in a single piece.

Pyrite oxidizes in high humidity, so dry storage is mandatory. Rock crystal is robust and suitable for everyday use.

A collector's item with didactic value, suitable as a teaching cabinet piece.