Magnesium oxide is a typical alkaline earth metal oxide, chemical formula MgO. White powder, melting point 2852 , boiling point 3600 , the relative density of 3.58 (25 ). It is soluble in acid and ammonium salt solution. Its slow action with water can produce magnesium hydroxide. It can be dissolved in carbon dioxide aqueous solution to produce magnesium bicarbonate. In the air, it can gradually absorb moisture and carbon dioxide. Heating releases irritating fumes. Magnesite (MgCO3), dolomite (MgCO3 CaCO3) and seawater are the main raw materials for the production of magnesium oxide.