QUARTZ crystal with SPHALERITE (miniature)
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.
Sphalerite, a sulfide mineral represented by the chemical formula (Zn, Fe)S, serves as the principal ore for zinc extraction. This mineral occurs in various types of deposits, predominantly within sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide formations. It is commonly associated with other minerals such as galena, chalcopyrite, pyrite, as well as calcite, dolomite, quartz, rhodochrosite, and fluorite.