Copper(I) sulfide is a black, crystalline solid with the chemical formula CuS. It is also known as chalcocite and covellite and is an ionic compound of copper with sulfur. It is insoluble in water and dilute acid and decomposes rapidly when exposed to nitric acid. It is used as an antifouling paint, solid lubricant, and a catalyst for various reactions. It is also a photoresistor for the fabrication of thin-film semiconductor devices.
Copper sulfide ores are concentrated by froth flotation, which involves attaching the fine copper-sulfide mineral particles to bubbles that then float out of a water-ore mixture. The process can be made selective by using reagents that make some of the copper-sulfide minerals water-repelling (hydrophobic) while leaving other minerals wet (hydrophilic). The resulting concentrate grade is usually around 30% Cu, higher with chalcocite and bornite minerals.
Safeopedia Explains copper 1 sulfide formula
The empirical formula of copper sulfide is Cu(I)S. The first two sulfides are monovalent and the third is polyvalent. The sulfide is soluble in ammonia but insoluble in water and nitric acid and it is toxic. It occurs naturally as the copper-sulfide mineral chalcocite.
Copper sulfide has a tetrahedral structure with 24 crystallographically distinct copper atoms in each unit cell. It is stable at room temperature but twinning forms at high temperatures and the crystalline structure changes to an orthorhombic form. American Elements produces copper sulfide to many standard grades when applicable, including Mil Spec; ACS, Reagent and Technical Grade; Food, Agricultural and Pharmaceutical Grade; Optical Grade and USP/BP.