I found this stone in an old wall and knew I had to make a sink out of it. For your consideration here is a boulder carved and polished into a sink. I have made sinks for everything from penthouses to rustic log cabins. This boulder is a pudding stone or conglomerate . Stones like this that are solid are kind of rare. The only place that I have found them consistently are in Alaska . The geologic conditions there force stones together when the tectonic plates move. This stone is actually from Indiana. The sink is about 5 inches deep 10 inches wide and 12 inches long inside dimensions.