Boulder-sized clasts are located in some stratified rocks, such as coarse conglomerate and also rock clay. In geology, a rock is a rock fragment with size greater than 256 millimetres (10.1 in) in diameter. While a boulder might be little adequate to relocate or roll manually, others are incredibly huge. In common use, a rock is as well large for a person to move. Smaller rocks are typically simply called rocks (American English) or rocks (In British English a rock is larger than a stone).