Properties

Magnesium oxide crystals - SEM image (1350x)
General
Name	Magnesium oxide
Chemical formula	MgO
Appearance	White solid
Physical
Formula weight	40.30 g/mol
Melting point	3073 K (2800 °C)
Boiling point	3873 K (3600 °C)
Density	3.58 ×103 kg/m3
Crystal structure	Cubic FCC
Solubility	0.00062 g in 100 g water
Thermochemistry
ΔfH0liquid	? kJ/mol
ΔfH0solid	? kJ/mol
S0solid	? J/(mol·K)
Misc.
Thermal conductivity	42 W m-1K-1 at 273 K
Coefficient of thermal expansion	10.8 ×10-6/K at 273 K
Specific heat capacity	877 J kg-1 K-1
Dielectric constant	9.65 at 1 MHz
Young's modulus	250 GPa
Shear Modulus	155 GPa
Bulk modulus	155 GPa
Poisson's ratio	0.18
Safety
Ingestion	No known effect.
Inhalation	Causes irritation of upper respiratory tract.
Skin	Causes irritation.
Eyes	Causes irritation.
SI units were used where possible. Unless otherwise stated, standard conditions were used. Disclaimer and references

Magnesium oxide is a white solid mineral that occurs naturally as periclase and is a source of magnesium. See also oxide.