It is manufactured at high temperature in an electric resistance furnace with quarts sand petroleum coke as its main raw materials. Its hardness is between fused alumina and synthetic diamond. Its mechanical intensity is higher than fused alumina. It is brittle and sharp and has electrical and heat conductivity in some degree, suitable for grinding hard and brittle metal, non-ferrous metal, like copper, brass, aluminum, and magnesium, and non-metallic materials such as gem, optical glass, rock, leather, rubber, etc. It is also widely used as refractory material and metallurgical additive.