Silicon carbide:

• Preparation: It is a bluish-black crystalline artificial mineral with hardness between corundum and diamond.
• It is made by subjecting a mixture of silica and carbon (coke or coal) to high temperature (1650-2200 °C) in an electric furnace

$SiO_2+3C→SiC+2CO↑$

• It is very hard, chemically unreactive, can withstand the action of high temperature without damage, but it is not tough and is somewhat brittle. It is mainly used in cutting-wheels, abrasive papers and clothes. It is extensively used for grinding of materials of low tensile strengths like cast iron, brass, bronze and many more.