This is a river rock which was relatively “soft” as far as rocks go, took 18 days (at 8-12 hours per day), and destroyed over 200 diamond-tipped tools! I believe it is marble. It weighs 4 pounds 2 ounces, is around 5 inches long and 4.5 inches tall. It is signed on bottom and is not for sale. I have yet to find another stone this white! Click the image for better view.