1 Stop’s #57 stone is a coarse aggregate that is known for its durability. 1 Stop Landscape Supply manufactures our #57 rock from clean concrete. It ranges from 3/8” – 1 ½” in size. #57 rock can be used for multiple purposes. For example, #57 rock can be used in ready mix concrete, the base for retaining walls, as a base for driveways, pipe bedding. #57 rock is also sometimes used as a top dressing for gravel roads.