Sorel cement
Sorel cement (also known as magnesia cement) is a non-hydraulic cement first produced by Frenchman Stanislas Sorel in 1867.
The cement is a 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. A variant uses zinc oxide with zinc chloride instead of the magnesium compounds.