In order to manufacture articles in the form of blocks of conglomerate stone material, two mixes, i.e., a primary mix and a secondary mix, are prepared in two separate mixers operating under a vacuum.The primary mix is prepared with granulated stone material having at least one characteristic (such as colour and/ or particle size) different from that that of the granulated material used in the secondary mix. The two mixes, which have a volume ratio such that the primary mix is preponderant, are mixed under a vacuum so that the secondary mix is mixed partly together with the primary mix, forming inclusions. The resultant final mix is fed to a formwork, which is then transferred to a vacuum vibrocompression section and then to a hardening section.