QUARTZ with PYRITE, HUARON, SAN JOSE DE HUAYLLAY DISTR. CERRO DE PASCO, PERU (small cabinet)

Pyrite, commonly referred to as fool's gold, is an iron sulfide with the chemical formula FeS2, also known as iron (II) disulfide. It is the most prevalent sulfide mineral found in nature.

Quartz is a robust crystalline mineral made up of silica, or silicon dioxide. Its structure consists of a continuous arrangement of SiO4 silicon-oxygen tetrahedra, where each oxygen atom is shared between two tetrahedra, resulting in the chemical formula SiO2. This classification places quartz as a framework silicate mineral in terms of structure and as an oxide mineral in terms of composition. It ranks as the second most prevalent mineral in the continental crust of Earth, following feldspar.