Sulfates are natural salts of sulfuric acid, where the structure contains sulfate anionic groups in a tetrahedral form that are always isolated, unlike those in borates and silicates. This class also includes oxysalts of selenium, tellurium, and chromium acids.

Over 200 types of sulfate minerals are known, but only a few appear frequently in nature. The most well-known sulfate minerals are anhydrite, barite-an important mineral raw material in the oil industry and for producing white paint and smooth paper, celestine, anglesite, halcanthite-also known as blue vitriol, a substance used to protect plants, epsomite-also known as Epsom salt, which is used in medicine, polyhalite, and gypsum-an important mineral raw material used in construction and art.

They can form as products of the oxidation of sulfide ore deposits, through evaporation (evaporation), crystallization from seawater, or their formation is related to hydrothermal processes (hot water solutions) and volcanic gases.