Abstract: Pieces of marble or similar natural stone having a plurality of plane faces are stacked in a liquid-tight container. Said pieces are arranged with their plane faces facing each other so as to form a plurality of parallel layers. Thereafter, a vacuum is applied in said container and, while maintaining the latter under vacuum, a fluid hardenable binding composition, such as a synthetic resin, is then poured into said container. Said composition flows down through the interstices existing in and around the stack of pieces, until it completely covers said stack. Thereafter, the inside of the container is brought to atmospheric or superatmospheric pressure, thus causing said binding composition to thoroughly penetrate into all said interstices and into all the cavities of the pieces opening on their surface, and then said binding composition is allowed to harden.

Abstract: A block to be consolidated, which is contained in a bag made of liquid tight flexible sheet material, is enclosed in a pressure tight container with the open mouth of the bag open upwardly. While the vacuum is maintained in the container, a liquid medium is supplied into the container and around the bag until the liquid medium reaches a level lower than the level of the open mouth of the bag, after which the container is evacuated into a vacuum state, and then a fluid hardenable resin composition is fed into the bag, through its open mouth, until the block is immersed in said composition. Thereafter, the vacuum is released from the container, so that the fluid resin composition deeply penetrates into all the cavities of the block which are open to the outside, and finally the resin composition is allowed to harden, whereby a consolidated block is obtained.