To cut stone, first assemble all the necessary tools, including a hand sledge, safety glasses, a chisel made of carbide or other very tough material and a wax pencil. Next, mark the area where you are going to cut with a waxed pencil and lay the stone on the ground.
Make sure the stone is positioned with the less attractive, or waste side, down. Next, place the tip of the chisel on the wax pencil line and strike the stone once with the sledge. Then move the chisel slightly so that it's half on the unscored stone and half on the score mark. Bring the sledge down as often as necessary until the waste flakes off.
Another way to cut stone is to bore a line of holes or carve a trench into the stone, then use a wedge to split it. Alternatively, bore holes in the stone and insert shims into the holes. Place a wedge between the shims and tap the wedge until the stone splits. Hard stone such as granite needs fewer holes than soft stone such as marble.
Circular power saws that use dry or wet diamond saw blades are another way to cut various types of stone. You can even use a handsaw if the stone is very soft.