The present invention relates to an icosahedral, quasicrystalline compound or compound present in the form of an approximant having the nominal composition: Ti.sub.vCr.sub.wAl.sub.xSi.sub.yO.sub.z, in which v=60-65; w=25-30; x=0-6; Y=8-15; z=8-20; and in which the atom percent of oxygen is in the range of between 8 and 15%, and that of aluminum in the range of between 2 to 5%. Due to their layered structure and ceramic intermediate layers, compounds of this type exhibit excellent properties, in particular for use as coatings for gas turbine components, such as for example, rotor blades or guide vanes.