THE GIRL'S GUIDE TO GEM CUTTING April 15 2016
Lapidary, the art of working or cutting in stone, only applies to working with small gem materials, and you will hear the word often in reference to gem cutting. There are four basic styles of gem cutting: tumbling, cabbing, faceting, and carving.
The simplest form of gem cutting is tumbling. This is where the rough material is put in a revolving barrel with abrasives. Progressively finer abrasives are used until a polish is obtained. This process closely resembles what happens to rocks in a stream or on the beach, except that the level of polish is much higher.
CABBING - CABOCHON CUTTING
Cutting cabochon, or as it is more commonly known, cutting “cabs,” is probably the most common form of gem cutting. Cabs are gems that are cut with a flat bottom and a curved or domed top. If you can envision an opal or a piece of turquoise, you are looking at a cab. Cabs have distinct resale value based on the material they are cut from, and their cutting can be profitable.
Faceting is the style of cutting that has the greatest profit potential. If you can envision a diamond in an engagement ring, you are looking at a faceted gem. The surface of a diamond is covered with several geometrically arranged, flat surfaces. Each of these flat surfaces is called a facet. The gem is faceted by a faceter on a faceting machine. The purpose of faceting is to bring out the brilliance of a gem. That is where the light entering the stone is reflected off the bottom facets and returned to the viewer. Brilliance should not be confused with dispersion or fire, which is the multicoloured flashes you see coming out of diamonds and some other gems.
Carving is the most challenging of the lapidary arts and there are very few recognised experts in the field. To be successful, one must have a distinctive artistic sense and a thorough understanding of the principles of lapidary. Unlike working in wood or metal, the materials present define limits as to what can be done. There are several types of carving. One of the best known is cameo. These are usually cut from sea shells or agates, but they can be carved from almost any material.
Cabochons are often carved. If the design is cut into the top, it is called an intaglio, or a relief carving. If the design is carved on the back, it is a reverse intaglio. Some carvings are not designed to be used in jewelry; they are cut simply for their beauty. These are classed as stand alone carvings.
Written by Anaita Thakkar for Lustre Jewellery