How to Facet Gems

Unfortunately, mankind is never satisfied with a thing of beauty; he must improve on this beauty. He does so this with practically everything that the hand of man touches. This even includes the beautiful flowers of nature the clear crystals that make up gemstones. He does this by a faceting a set of new faces on the original crystal providing it is clear enough and shows all imperfections.

The faceting process is done with a specialized machine that is called a faceting machine. This is actually a grinding machine that uses diamonds as the abrasive. There is a hand piece to hold the stone to be polished onto a dop stick. The machine has a mast that allows a hand piece the freedom to move 360° around the mast. The hand piece itself is placed in a 90° quadrant that can be mechanically set at any angle the operator desires. The hand piece also includes a built-in indexing head so that the operator can index to love ever setting he desires.

A faceting machine itself is like a tank with the working parts inside the tank. This includes both the mast and a grinding wheel attached to one arbor that comes vertically up through the bottom of the tank. This arbor is attached by a belt to electric motor. This applies the power to do the grinding.

The dop stick is usually made in pairs, one that is flat on the end, and the other has an internal recess of about 60°. A pre-formed gemstone is attached to the dop stick having the internal recess. This is done using a hot wax very similar to sealing wax that is called dop wax. This wax comes in sticks that are about three quarters of an inch square at about 6 inches long. In use the end of the dop wax is melted and the flame of an alcohol lamp. A drop of this wax is applied to the end of the dop stick, and while it is still soft the pre-formed gemstone is inserted into the wax. This is then allowed to harden so that firmly grasps the gemstone. A special tool is then used on the mast to grind the table facet of the gem. This is a flat facet located at the top of the gem, and is the largest facet found on a gem.

Once the top of the gem has been ground flat it is then polished. This is done by replacing the grinding wheel with a lapping wheel. There are several different polishing compounds available but the most commonly used is cerium oxide. These are available as pre-charged sand plastic discs about 6 inches in diameter. Once the table facet has acquired a high polish so that it looks like a piece of glass the other so called crown facets are ready to be applied.