Bricks; Sand; Slate; Artificial stone; Building stone; Ceramic tiles; Ceramic wall tiles; Ducts, not of metal, for ventilating and air-conditioning installations; Glass mosaics for use in building construction; Marble; Non-metal water pipes; Non-metallic drainage pipes; Plastic conduit for drainage and irrigation; Sandstone for building; Staircases, not of metal; Tiles of ceramic for wall, floor or ceiling; Water-pipe valves, not of metal or plastic; Works of art of stone, concrete or marble; Aquarium gravel; Aquarium sand; Scented sand for decorative purposes