In normal temperature, it’s with three hydrates. Light one is white, easily fragile or loose white powder. Odorless. Relative density is 2.2. Melting point is 350℃. It’s stable in the air. When heated to 700℃, it will become magnesium oxide. It’s hardly soluble in water, but it’ll bring a slight alkaline reaction. It can not be soluble in ethanol but it could be soluble in olefine acid with sparkling.