Sandstone, is a form of rock commonly used for sculpture. It is very soft as far as rock hardness goes, and is therefore fairly easy to carve, sculpt or shape.
Sandstone is commonly used by stone sculptors and by landscape gardeners. In some countries where sandstone is readily available it is also used as a natural building material. The city of Sydney in Australia, for example is geographically located entirely on sandstone, with it being so readily available many buildings and gardens feature sandstone, and sandstone sculpture is very popular.
There are several forms of sandstone by which is is sold, such as: Flagstone (pictured), sawnstone, ripped sandstone boulders, split sandstone blocks, hydra-split sandstone and diamond cut sandstone.
Sandstone for sculpture is best selected in person from a sandstone quarry, or by special ordering a custom sandstone block cut to your exact size requirements. Some Sculpture Supply Stores offer this as a service.
If you want to become a stone mason or learn how to sculpt sandstone, try taking a Sculpture Class.