Potassium chloride is extracted from minerals sylvite, carnallite, and potash. Bischofite is used in the production of the industrial Sorel cement and synthetic carnallite. Closer to 10 percent sylvite followed by Carnallite form. Carnallite and bischofite are important sources of magnesium. Evaporite deposits may contain potassium minerals such as sylvite and carnallite. It is often accompanied by anhydrite, carnallite, halite, and kieserite. Carnallite minerals are mineral sediments known as evaporites. It occurs in association with halite, carnallite, polyhalite, anhydrite, boracite, sulfoborite, leonite, epsomite and celestine. In carnallite, the water molecules enclose the magnesium ions. Caesium chloride occurs naturally as impurities in carnallite (up to 0.002%), sylvite and kainite. Field indicators of carnallite are environment of formation, absence of cleavage, and fracture. Carnallite is also deliquescent in high humidity. Carnallite has corner- and face-sharing. The potassium that carnallite contains fuses easily within a flame, creating a violet color. Carnallite is a minor source of magnesium worldwide; however, it is Russia's main source.