Magnesium hydroxide is defined as an inorganic compound obtained by precipitation process between the magnesium salts and sodium, or potassium and ammonium hydroxide. Brucite, which is a form of natural magnesium, is used for commercial purposes such as fire retardant while most industrially used magnesium hydroxide is produced synthetically. Brucite may also crystallise in cement and concrete in contact with seawater. Magnesium hydroxide has chemical formula of Mg(OH)2. Commercial and industrial magnesium hydroxide is chemically manufactured from seawater or brine. Magnesium hydroxide is known as milk of magnesia owing to its milk-like appearance. This compound is less soluble in water. It possesses properties such as flame retardancy, low corrosiveness, and low toxicity.