the present invention relates to a process for making a product of artificial rock and a product thus made for use , in particular , in aquariums , tanks , swimming pools and the like ; the process comprises the following operating steps : carrying out a first deposition of a mixture of powdered aggregates , resin , additives , within a cast or mould ; catalyzing the mixture of said first deposition ; covering the surface thus obtained with isophtalic or bisphenolic polyester resin ; carrying out a second deposition of powdered aggregates , resin , additives ; covering the surface derived from the second deposition with a layer of structural component and with resin ; polymerizing the intermediate product thus obtained ; covering the surface thus obtained with a layer of gel ; polymerizing the product thus obtained ; removing the product from the mould ; subjecting the product to a heating treatment .