A core, for example made of steel, is provided with a coating formed by an agglomerate obtained by means of hardening of a mixture comprising a granulated stone material, preferably of the type having a high hardness factor and light colour, and a hardening resin, preferably an epoxy resin. For the manufacture of the roller, a form work having a cavity for housing a core is prepared so as to provide an interspace which is filled with the aforementioned mixture, following which compacting of the mixture present in the interspace and then the resin hardening step are performed.