Zinc sulfide is an inorganic compound with the chemical formula of ZnS. This is the main form of zinc found in nature, where it mainly occurs as the mineral sphalerite. Although this mineral is usually black because of various impurities, the pure material is white, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics.
ZnS powders containing different concentrations of sulfur vacancies
Mixtures of zinc and sulfur react pyrotechnically, leaving behind zinc sulfide.
Sphalerite is a sulfide mineral with the chemical formula (Zn,Fe)S. It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite, calcite, dolomite, quartz, rhodochrosite, and fluorite.
Black crystals of sphalerite with minor chalcopyrite and calcite
Sphalerite fluorescing under ultraviolet light. (Sternberg Museum of Natural History, Kansas, USA)
Faceted sphalerite, known by the name of Étoile des Asturies, one of the largest in existence. It actually comes from the Aliva mine, Cantabria (Spain). Cantonal Museum of Geology of Lausanne.
Sphalerite and barite from Cumberland Mine, Tennessee, USA