How Does a Rock Polisher Work?

Construction

• A rock polisher contains a cylindrical drum and a small motor. You carry out the process over a few weeks, beginning by placing stones of an appropriate size into the polisher drum. Added to this is a coarse abrasive grit made of silicon carbide and water. Switch the device on and allow it to run for about a week. Smaller polishers take smaller stones, and will quickly wear out if they are overloaded or if the stones are too large.

Polisher Action

• The polisher tumbles the stones continuously. As the machine jumbles the stones together, the grit and water form a slurry at the bottom of the machine. The rocks move up the sides of the polisher and then fall back into the slurry. The contact and action of the grit wear away the edges and leave the stones with a smooth surface. While the natural action of sand and waves slowly and unevenly polishes stones in a natural setting, a rock polisher accelerates the process with the constant motion and abrading of the stones.

Finer Grits

• Rock polishing is carried out with a series of finer grits, each used for about a week. After the first stage has rounded the stones with coarse grit, you add fine grit and allow the polisher to remove scratches and imperfections in the stones. In the third week, you continue with silicon sand, which removes the smaller and finer scratches.

Polishing

• In the final stage, you add a commercial polisher to the stones to give them an attractive shine. Titanium dioxide is one of several compounds used for the polishing stage. At the end of the process, the rocks come out smooth and rounded, and gleaming like gems. If you wish to more carefully preserve the original shape of the rocks, you can use a vibrating rock polisher, which instead of rotary action simply vibrates the rocks in place. Although they are more expensive, vibrating polishers work more quickly than rotary tumblers, and also use less grit.