Sorel cement

Sorel cement, which is named for its inventor, Frenchman Stanislas Sorel who first produced it in 1867, is a hydraulic cement mixture of magnesium oxide (burnt magnesia) with magnesium chloride with the approximate chemical formula Mg₄Cl₂(OH)₆(H₂O)₈, corresponding to a weight ratio of 2.5-3.5 parts MgO to one part MgCl₂. [Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.] This material, which is also called "magnesia cement," is usually combined with filler materials such as sand or crushed stone. A variant uses zinc oxide with zinc chloride instead of the magnesium compounds.

It is used for grindstones, tiles, artificial stone (cast stone), cast floors, and even artificial ivory (e.g. for billiard-balls). It can withstand 10,000 - 12,000 psi of compressive force whereas standard Portland cement can only withstand 2,000 psi.

Its chief drawback is its poor water resistance, making it unsuitable for construction applications. Additionally, it is expensive compared to standard concrete and gypsum.

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