When silicon solidifies on a carbon surface (pyrocarbon), the silicon carbide does not form a conti- nuous layer between the two phases. A simple crystallographic orientation exists between Si and SiC : (001)SiC is parallel to (111)Si, (100)SiC being parallel to (011)Si. SiC is thought to have formed from the carbon in solution in silicon. The carbon in solution is supposed to result from the carbon oxide CO which exists in furnaces.