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Identifying Synthetic Gems

Distinguishing between natural and synthetic gems is a critical skill for gemologists. Learn about gem making processes and the telltale signs they leave.

14 Minute Read

Basic Terminology

You should know the following definitions:

  • Natural Gems – formed in the Earth
  • Synthetic Gems – duplicates of natural gems grown in a lab
  • Homocreates – synthetic gem materials with no natural counterparts
  • Imitations – gemstones or other materials presented as other kinds of gems

You can find more information on these terms in our guide to gem classification.

Keep in mind that some of these definitions can overlap. For example, you may find a synthetic corundum stone offered for sale as an imitation aquamarine.

What to Look For First

Very fine clarity may be the first indication you’re dealing with a synthetic, since few natural gems are clean to 10X, much less anything higher. If you can’t find natural inclusions with a loupe, you probably have a synthetic. While this isn’t proof, it’s a strong clue. You should investigate further.

Unfortunately, the opposite isn’t necessarily true. While most synthetics are very clean, you’ll find some stinkers out there. Don’t assume you have a natural gem just because it contains many inclusions.

Synthetic gems mimic the best of the natural gem world, so expect them to show fine color. If you’re examining a stone with…

Donald Clark, CSM IMG

The late 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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