Magnesium chloride is a colourless crystalline solid. It is very hygroscopic in nature. It is soluble in water and alcohol. It can be prepared by heating hydrated magnesium chloride crystals in a current of dry hydrogen chloride or by heating magnesium ammonium chloride. Anhydrous magnesium chloride crystallizes from magnesium chloride hexahydrate as leaflets.

Along with its health and public safety uses, magnesium chloride is also used in a number of industrial processes, including textile production. It is particularly common in printing mills and other paper textile manufacturing centres, where it is used to neutralize and clean wastewater by-products.