demantoid Barion cut - faceting stylesdemantoid Barion cut - faceting styles

Custom Gem Faceting Styles


Gem cutters can choose from many faceting styles. Learn about the most common custom cutting techniques and pick one that suits your needs and skill level.

6 Minute Read

Custom gem cutters can choose from many faceting styles. Some versatile cutters use a wide variety. Others prefer to cut the most difficult designs on large and high-value pieces. Still others prefer simple cuts for nothing more than occasional gifts to friends and relatives. Fortunately, everyone can find the approach that suits them best.

Calibrated Gem Cutting Machines versus Jam Peg

Most custom cutters use calibrated machines. Every setting is precisely controlled. Factories, on the other hand, use simple “jam peg” machines for the majority of their cutting. Factory cutters attach a rough gem to a long peg, which is inserted, “jammed,” into a vertical plate with multiple holes. The holes give the cutter an approximate angle. Skill and experience determine the rotation.

Cutting with a jam peg machine requires great skill, but the work is never precise. Since the angle and location of a facet greatly affect the brilliance of the finished gem, this method usually produces less than ideal gems. Factories use it because of the minimal time required.

Calibrated machines take less skill to operate than a jam peg but give superior results. However, finishing a gem takes much longer. Nevertheless, the quality difference is so remarkable…


Donald Clark, CSM IMG

Donald Clark, CSM founded the International Gem Society in 1998. Donald started in the gem and jewelry industry in 1976. He received his formal gemology training from the Gemological Institute of America (GIA) and the American Society of Gemcutters (ASG). The letters “CSM” after his name stood for Certified Supreme Master Gemcutter, a designation of Wykoff’s ASG which has often been referred to as the doctorate of gem cutting. The American Society of Gemcutters only had 54 people reach this level. Along with dozens of articles for leading trade magazines, Donald authored the book Modern Faceting, the Easy Way.

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