This Preservation Technology Update briefly reviews current methods for restoring stone in buildings. It cites water spraying to clean exterior marble, but notes the need for filtration and purification of the water used. Pressure washing may suffice on polished exterior granite, but this and textured stone often requires chemical treatment in addition. Cleaners for granite frequently contain hydrofluoric acid requiring the shielding of adjacent marble, aluminum, or glass as well as prompt rinsing. Paint stripping with alkaline cleaners requires pressure washing and safe sludge removal. For cleaning interior stone the author cites numerous techniques and materials: sponging with neutral or mildly alkaline detergents; a bicarbonate gel used in Italy; poultices with carefully chosen liquid cleaners such as oxalic acid for iron stain in granite or ammonium citrate in marble, or bleach such as hydrogen peroxide or calcium hypochlorite. Coatings and consolidants noted with cautions include acrylic sealer, silicones, stearates, barium hydroxide, ethyl silicate, alkyl silanes, and silicone-modified acrylics. Mortars and other materials for pointing, patching, and repair of stonework are also cited.