Limestone is a sedimentary rock composed mainly of calcite, which is a mineral made up of the remains of organisms such as clams, corals and brachiopods. Depending on the quality of the limestone, there can be small to large amounts of sand and silt in the rock. Limestone is often used as a building material, though is not as strong as some other rocks, such as sandstone. It can also erode through exposure to acidic conditions. With the proper tools and application, it is possible to break up large chunks of limestone.
Move the piece of limestone into an area where you have space to work. Using heavy tools and drills emits limestone dust and debris into the air, so working outside is a preferable location. Ask an assistant to help you lift pieces of limestone that are heavy, or use carrying equipment, such as a wheelbarrow, to move the limestone to your work area.
Draw a straight line on the piece of limestone with a pencil. This line is where you would like the limestone to break.
Drill holes along the line using a diamond-tipped drill bit or any heavy-duty drill bit that will drill through stone. The size of the drill bit is up to you, though the larger the size that you use, the easier the limestone will break. Opt for a 1/4 inch to 1/2 inch bit. Try to drill two to three inches into the limestone piece.
Insert metal wedges into the drilled holes.
Tap along the line of the wedges one at a time with a metal hammer. As you go along the line tapping the wedges, you will hear the pitch increase when you strike the wedges. Keep tapping along the line of wedges until the limestone cracks. Usually, if you have drilled and hammered evenly along the line, the limestone will crack along the straight line that you drew.
Break any additional large chunks of limestone with a pitching tool. A pitching tool is often used by sculptors when working with stone. Place the edge of the pitching tool into a hard edge of the limestone, then hit the pitching tool with a hammer so that the tool drives into the limestone. Large chunks of limestone break off each time you strike the tool. If you want to break large chunks into smaller chunks, take the larger chunk and place it on the ground. Hit the large chunk with a metal mallet or hammer to break the limestone into smaller pieces.
Wear safety goggles when working with rocks and electric tools. Wear safety gloves to protect your hands from sharp or crumbling rock. Never try to break off large chunks of limestone part of a supporting structure, such as a freestanding sculpture, rock formation or cave.