single displacement reaction between copper(II) chloride and aluminium metal. In the US in 1993, approximately 21,000 tons were produced, not counting the amounts consumed in the production of aluminium. Hydrated aluminium trichloride is prepared by dissolving aluminium oxides in hydrochloric acid. Metallic aluminium also readily dissolves in hydrochloric acid ─ releasing hydrogen gas and generating considerable heat. Heating this solid does not produce anhydrous aluminium trichloride, the hexahydrate decomposes to aluminium hydroxide when heated: Aluminium also forms a lower chloride, aluminium(I) chloride (AlCl), but this is very unstable and only known in the vapour phase. Natural occurrence Anhydrous aluminium chloride is not found as a mineral. The hexahydrate, however, is known as the rare mineral chloraluminite. A more complex, basic and hydrated aluminium chloride mineral is cadwaladerite. Safety Anhydrous reacts vigorously with bases, so suitable precautions are required. It can cause irritation to the eyes, skin, and the respiratory system if inhaled or on contact. See also Aluminium monochloride References External links International Chemical Safety Card 1125 Index of Organic Synthesis procedures that utilize AlCl3 The period 3 chlorides MSDS Government of Canada Fact Sheets and Frequently Asked Questions: Aluminum Salts Chlorides Metal halides Aluminium compounds Inorganic compounds Reagents for organic chemistry Deliquescent substances Acid catalysts