Description

Magnesium oxide, or magnesia, is a white solid mineral that occurs naturally as periclase and is a source of magnesium (see also oxide). It has an empirical formula of MgO. It is formed by an ionic bond between one magnesium and one oxygen atom. Magnesium oxide is hygroscopic in nature and care must be taken to protect it from moisture. Magnesium hydroxide forms in the presence of water (MgO + H2O � Mg(OH)2), but it can be reversed by heating it to separate moisture. Applications Desiccant; Medical In medicine, magnesium oxide is used for relief of heartburn and sore stomach, as an antacid, magnesium supplement, and as a short-term laxative. It is also used to improve symptoms of indigestion. MgO is used as an insulator in industrial cables, as a basic refractory material for crucibles and as a principal fireproofing ingredient in construction materials. It is used as a reference white color in colorimetry, owing to its good diffusing and reflectivity properties. It is used extensively in electrical heating as a component of "CalRod"-styled heating elements. Pressed MgO is used as an optical material.