Calcium sulfide is a chemical compound that is formed by the combination of calcium and sulfur. The chemical formula of calcium sulfide is CaS. This chemical compound is widely used in various industries such as in the production of pigments, food preservation, and wastewater treatment. Calcium sulfide is also known by several other names such as lime sulfide, calcium sulphide, and sulfurated lime. Its synonyms also include calcium(II) sulfide, calcium monosulfide, dicalcium sulfide, and calciolate. Calcium sulfide is an odorless, white or grayish-white powder that is corrosive and can cause severe skin and eye irritation.