You have probably seen the work of a skilled stone mason, like the beautiful natural rock columns in hotels or on the side of that fancy house, but it takes a lot more work than you would think. When you look at the finished work of a stone mason, it appears that all of the stones were carefully selected to fit perfectly into the design, but they weren't. Stones rarely fit together perfectly, and this means that the stone worker often has to shape them to fit where he needs them to. Using a saw would give you a sawblade finish, which doesn't look good with natural stone. Check out the video below to see how you cut a rock in half with hand tools.
Whether you want to cut a rock in half, or just trim off a little bit on the outside to make it fit into your pattern, you will have to use a hammer and a form of wedge. You may be able to just break a rock by hitting it with a hammer, but then you can't control the shape. If you want to be precise, it's time to bring out the stone drill and start making holes in that rock. Once you do that, you shove wedges and shims into the holes and start hammering away. Be careful when you hammer, you need to drive the shims in slowly and equally. Even when you take time and be careful, sometimes it doesn't work like you had planned and you have to just give up and try a different stone.
If you have a smaller rock, you can use a tool called a hand tracer, which is like an axe for rocks. By hitting the tracer repeatedly along a line, you can make stones split along the lines you need.
[Image Source: This Old House]
So now you are ready to become an expert stone mason! If you don't have patience, this work is probably not for you, but you can make some beautiful things with these simple stone shaping tricks.