Magnesite
a widely occurring mineral, consisting of magnesium carbonate, MgCO3. It is mined in California, British Columbia, New Jersey, New York, Washington, Quebec, India, Austria, and Greece. It occurs in three forms-crys- forms talline, massive, and earthy, the two latter being white in color and frequently mixed with other magnesium salts. Its principal use is in the manufacture of refractory linings for furnaces and retorts, and for this purpose it is of great value in the cement and metallurgical industries.
It is also used in the preparation of Epsom salts (magnesium sulphate) and other salts of magnesium. A strong cement is made by mixing calcined magnesite with chloride of magnesium. Other uses are in the manufacture of paper and pigments and for heat insulation.
MAGNESIUM MAGNESIUM (-ne'shium) (Latinized from Magnesia, a city in Asia Minor), in chemistry, a diatomic metallic element; symbol, Mg; at. wt. 24.4; sp. gr. 1.743.
Fuses and volatilizes at a red heat. Magnesic sulphate (Epsom salts) was known in the middle of the 17th century, but the metal was first isolated by Davy. The compounds of magnesium are widely distributed in nature, occurring as magnesite, MgO"CO; ophite or serpentine, MgO"Si2O; talc, MgO" SisO6; dolomite, kainite, te, epsomite, etc.