sulfider

Sulfider, or sulfide in many contexts, refers to chemical compounds that contain sulfur in the negatively charged sulfide form (S2−) or sulfur bonded to a metal or nonmetal in a way that is characteristic of sulfide chemistry. In inorganic chemistry, sulfides are binary compounds of sulfur with metals or nonmetals, often displaying ionic or covalent bonding with varying degrees of character. In mineralogy, sulfide minerals are discrete minerals composed of metal cations combined with sulfur, yielding a wide range of compositions and structures.

Common sulfide minerals include pyrite (FeS2), galena (PbS), sphalerite (ZnS), and chalcopyrite (CuFeS2). These minerals are important ore sources for metals such as iron, lead, zinc, copper, and mercury. The crystal structures of sulfides range from simple binary sulfides to more complex solid solutions, and some exhibit metallic luster and conductive properties. In addition, certain sulfides, such as zinc sulfide (ZnS), are wide-bandgap semiconductors used in optics and electronics.

Formation and occurrence: sulfides form in various geological settings, including hydrothermal veins, magmatic differentiation zones, and sedimentary environments with reducing conditions. Bacterial processes can also influence sulfide formation and alteration in natural systems.

Industrial and environmental considerations: sulfide ores are processed to extract metals, often involving roasting or smelting that releases sulfur dioxide unless controlled. The oxidation of sulfides in the environment can lead to acid mine drainage and the release of toxic hydrogen sulfide under anaerobic conditions. Sulfides should be distinguished from related sulfur oxyanions such as sulfates and sulfites, which involve higher sulfur oxidation states.