Magnesium oxide (MgO), or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium. It has an empirical formula of MgO and consists of a lattice of Mg2+ ions and O2− ions held together by ionic bonding. Magnesium hydroxide forms in the presence of water (MgO + H2O → Mg(OH)2), but it can be reversed by heating it to separate moisture.

One of the components used to make cement
Used by libraries for preserving books
Used in medicine to relief heartburn and sour stomach
Insulator in industrial cables
Component of tubular construction heating elements
Used as a protective coating in plasma displays

Minimum Assay: >96%
Molecular Formula: MgO
Molecula Formula: 40.30
Solubility in water (% weight): Insoluble in water
Melting Point: 2852°C
Boiling Point: 3600°C
Refractive Index: 1.736
Substance insoluble in acetic acid: <0.1%
Substance soluble in water: <1.8%
Chloride (Cl): 0.04%
Sulphate (SO4): 0.003%
Heavy metals (as Pb): 0.000036%
Calcium (Ca): 0.748%
Iron (Fe): 0.0006%
Arsenic (As): <0.0004%
Loss on ignition @ 990 C: 8.0%

Hazard Phrases: Not considered harmful under normal laboratory conditions

Cas No: 1309-48-4
Einecs No: 215-171-9