UK sculptor Stephen Kettle works primarily with thin pieces of stone slate, using the material to build figures, busts, animals, and other objects. His most famous piece is a sculpture of Alan Turing (first four images) on display at Bletchy Park in Britain. The piece took 18 months to build and weighs 3,000 pounds (1.5 tons). (images via nolan huzenga, ken dougals, davkav, and the artist)