Magnesium oxide, commonly known as magnesite, also known as magnesium oxide, magnesium oxide is alkaline oxide with alkali oxides continuity, belonging to cementitious materials. White or light yellow powder, odorless, tasteless, non-toxic, is typical of an alkaline earth metal oxide, the chemical formula MgO. White powder, mp 2852 °, the boiling point of 3600 degrees, the relative density of 3.58 (25 degrees).