Magnesium Oxide (chemical formula: MgO) is an oxide of magnesium, an ionic compound. At normal temperature it is a white solid. Magnesium Oxide exists in natural form in the form of magnesite. It is the raw material for smelting magnesium.
Magnesium Oxide has high fire resistance and insulation properties. After burning above 1000 degrees Celsius, it can be turned into crystal, rising to 1500-2000 degrees C and then dead burned Magnesium Oxide (that is, magnesia) or sintered Magnesium Oxide.