Pure silicon carbide is colorless. Industrial production of silicon carbide due to the existence of some impurities, such as free carbon, iron, silicon, often show yellow, black, dark green, light green and other different colors, more common is black and light green.

Industrial silicon carbide is obtained by reducing silicon dioxide through carbon in a resistance furnace:

SiO2 (s) + 3 c (s) and SiC (s) + 2 co (g)

In the synthesis process, sawdust and industrial salt are often needed to be added to it. The role of sawdust is mainly to form more holes at high temperature, so as to facilitate the discharge of gas in the reaction process, and industrial salt is to facilitate the removal of impurities such as Al2O3 and Fe2O3.

The initial reaction temperature is about 1400℃. The initial product is very fine crystalline β-SiC, which gradually transforms to α-SiC when the temperature rises to 2100℃. The final temperature of the reaction is generally selected in the range of 1900 ~ 2200℃, and the final product usually contains both α-SiC and β-SiC.