A method for production of crystalline coatings of the aluminosilicate polymorphs with the composition Al2SiO5 in order to create physically and chemically resistant layers on top of silicon substrates is reported. Formation of the crystalline phases was achieved by subjecting a reaction area of alumina layers on silicon substrates covered with silica to heat treatment under vacuum conditions at temperatures in a narrow range around 1100 degrees C. (c) 2005 Elsevier B.V. All rights reserved.