Faceting

From Edward J. Soukup’s book, “Facet Cutters Handbook”, copyright 1962, faceting is described as follows: “In faceting, we take a piece of transparent gem material and cut and polish facets on its surface at definite angles to bring out its hidden beauty and brilliance which would be quite lost if it were cut as a cabochon.

“Material other than transparent is also faceted and some of the deeply colored gem materials are cut not so much for brilliance as for color. Examples are emerald, ruby, and other richly colored stones.”

When demoing faceting, a frequently heard concern is: “Faceting is too immersed in math and mystery and is hard to do.” In truth, it could be if you desire to delve deeply into theory and gemstone design. But it is easy to learn to facet with today’s modern faceting diagrams and faceting machines.

Faceting diagrams are the recipe that you follow to cut a gem into a desired shape. They may seem complicated when you first look at them. After your first stone, the diagram makes logical sense. Faceting machines look very complicated but are actually easy to understand and use.

Remember, faceting is the art of placing small, flat windows (facets) on (usually) transparent gemstone material we call “rough”. The goal of the gemstone faceting design chosen for a particular piece of rough is to get the largest finished stone that maximizes the color and optical characteristics of it.

The faceting machine has settings that allow the orientation of the rough in three dimensions to properly place each facet. These settings come from the faceting diagram.

It is recommended that students start with a simple faceting diagram called the Simple Jack. It allows a new faceter to learn the faceting machine and a simple diagram. The most critical skill to learn is patience and not press the stone too hard on the lap. (Soukup defines a lap as follows: “Lap is the name given to the horizontal disc upon which the gem stone material is cut or polished.”) Pressing too hard doesn’t make the stone cut faster; it only changes the geometry of the cut. This means that the facets will not line up as expected. It takes about 2-3 stones before that skill is developed. After the Simple Jack, there is a recommended sequence of designs that build additional skills.

Plain yellow Sunstone is a good starter rough because it cuts fairly fast and polishes easily. It is also not expensive. Many want to cut the quartz (amethyst, citrine, smoky quartz, etc.) family because it is plentiful and not expensive. Natural quartz can be a challenge because of inclusions and occasional polishing issues.

There are also inexpensive synthetic gems that cut beautiful stones. Synthetic ruby and sapphire give practice before cutting natural stones from Montana or North Carolina.

Does it take longer to cut a sapphire compared to a Sunstone? A little, but not significantly. The diamond laps are much harder than the rough. As a matter of fact, softer rough can be more difficult to cut because there is a tendency to overcut a facet. The biggest factor in time to cut is the size of the rough.