BaCl₂, a salt that exists under normal conditions in the form of colorless crystals of the dihydrate Ba0₂·2H₂O with a density of 3.1 g/cm³. It loses water on heating to 100° C. Anhydrous barium chloride melts at 960° C. It is highly soluble in water (35.7 g per 100 g H₂0 at 20° C). Barium chloride is produced by roasting a mixture of barite, coal, and calcium chloride in combustion furnaces. It is used to combat agricultural pests and as a weighting and clarifying compound in tanning. Alloys of barium chloride with chlorides of alkali and alkali earth metals are used in the tempering and quenching of steel.