Stone Sculpting Tips and News

Splitting/cutting stone

Ravinder from India once drilled a series of small holes in a 6’ deep block of marble. He inserted feathers and wedges in each hole and hammered a little on them each hour for a couple of days. Sure enough, the stone developed a crack through the 6’ resulting in 2 blocks.

In marble, determine the bedding plane or grain direction. Drill the holes, insert the feathers and wedges and hit them sequentially. Most times the stone will split quickly. If not, wait a few hours or overnight before proceeding to allow the crystals to line up


For smaller or uneven stones a sandbag will stabilize the art-to-be. You can cut the legs off an old pair of jeans, fill it 2/3rds with play sand and seal the ends with plastic ties. I like using old truck tire tubes from my car repair place (sometimes a little hard to get, but free). I then cut them in half or thirds and similarly secure them with ties after filling partially with sand. This way if I hit the rubber “bag” with my grinder it just bounces off rather than cutting it open.

Heavy Lifting

Don’t. One wrong twist or extension can have long term implications. I got impatient and reached over the edge of my trailer to lift the edge of a heavy stone just a little. Cantilevered at a 90 degree angle I did the worst thing and pulled my lower back. That took over a year to heal. (If this should happen, get on a flat surface and start stretching immediately to minimize the damage.)

Of course always lift with your back straight and having your legs take most of the weight. But machines, even simply ones, make such sense. To move horizontally I pry the stone up a little with a pry bar and then insert two short 1-1.5” pipes so that I can roll the stone forward. I may have to lay a few boards on the floor or grass so the pipes will roll but I will slowly get to my destination.

You can lift a stone with a portable engine hoist (around $200). You can also tilt a stone forward and put a 2×4” block under it. Then lift the other side and put a block under that side. Now lift the opposite side and insert a second block of wood. Keep repeating this process until you reach the desired height. See this interesting Youtube of a guy building his own Stonehenge with any power tools: https://www.youtube.com/watch?v=-K7q20VzwVs

Remember never lose height. If a stone is already up in the air, like on a pickup bed or car trunk, do not throw it on the ground to be lifted anew onto a stand. Do everything you can to avoid having to lift it a second time.

Marble Formation

Marble is compressed shells and bones. Its adventure starts on the seabed where these calciums deposit and eventually become limestone. Then one of two forces, volcanic activity or tetonic plate movement, compress and heat the limestone changing its molecular structure. It is still calcium carbonate but has formed crystals that often shine. The Greek word for marble, mármaro, means sparkle. The colors in marble are from the other earth chemicals that leach into the stone as it is being formed: iron, copper, carbon, magnesium, etc.

Note that there are other calcium carbonates which are formed by waters that drip or flow such as travertine, calcite and onyx. These are all in the marble family. To test if a stone is marble or one of its cousins put a few drops of muriatic acid on the stone. If it fizzles it is most likely a calcium carbonate. (Do not breathe the fumes. The acid is neutralized with water.)