exceedingly hard, synthetically produced crystalline compound of silicon
and carbon. Its chemical formula is SiC. Since the late 19th century silicon
carbide has been an important material for sandpapers, grinding wheels,
and cutting tools. More recently, it has found application in refractory
linings and heating elements for industrial furnaces, in wear-resistant
parts for pumps and rocket engines, and in semiconducting substrates for
Silicon carbide was discovered by the American inventor Edward G. Acheson
in 1891. While attempting to produce artificial diamonds, Acheson heated
a mixture of clay and powdered coke in an iron bowl, with the bowl and
an ordinary carbon arc-light serving as the electrodes. He found bright
green crystals attached to the carbon electrode and thought that he had
prepared some new compound of carbon and alumina from the clay. He called
the new compound Carborundum because the natural mineral form of alumina
is called corundum. Finding that the crystals approximated the hardness
of diamond and immediately realizing the significance of his discovery,
Acheson applied for a U.S. patent. His early product initially was offered
for the polishing of gems and sold at a price comparable with natural diamond
dust. The new compound, which was obtainable from cheap raw materials and
in good yields, soon became an important industrial abrasive.
About the same time Acheson made his discovery, Henri Moissan in France
produced a similar compound from a mixture of quartz and carbon; but in
a publication of 1903, Moissan ascribed the original discovery to Acheson.
Some natural silicon carbide was found in Arizona in the Canyon Diablo
meteorite and bears the mineralogical name moissanite.