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Silicon carbide

Silicon carbide (SiC) or moissanite is a ceramic compound of silicon and carbon.

Most SiC is man-made for use as an abrasive (when it is often known by the trade name carborundum), or more recently as a semiconductor. The simplest manufacturing process is to combine sand and carbon at a high temperature, between 1600°C and 2500°C. Purer product can be made by the more expensive process of continuous vapour deposition. Its high melting point (above 1600°C) makes it useful for bearings and furnace parts. It is also highly inert. There is currently much interest in its use in electronics, where its high thermal conductivity, high electric field breakdown strength and high maximum current density make it more promising than silicon for high-powered devices.

Some SiC was found in a meteorite in Arizona by Dr. Ferdinand Henri Moissan, after whom the material was named moissanite. Naturally occurring moissanite is rare, having an appearance similar to that of diamond and a tetrahedral crystalline structure.

Gem quality Moissanite is manufactured exclusively by Charles and Colvard and is sold as a lower cost alternative to diamonds. In its gem form, Moissanite has an index of refraction between 2.65 and 2.69, somewhat higher than a diamond.