Wendi Mayerson, Chief Gemology Officer at Gemological Science International (GSI) in New York, recently offered insight into both the history of synthetic colored gemstones and how their marketplace differs from diamonds.
“The colored gemstone industry is different from the colorless diamond industry because buyers of colored gems have always had options with multiple gemstones looking like each other,” she explained. “For example, emeralds, tsavorites, demantoid garnets, and even some tourmalines are all green stones with overlapping ranges of color expression.
The discovery of mass-produced synthetic gemstones was very well-timed due to the popular Art Deco jewelry aesthetic in the 1920’s which featured lots of small colored gemstones that were calibre-cut with perfectly matched hues of deep saturation. In addition to being less expensive than natural gems, synthetics were a fantastic choice for this style because of their deep, uniform color and the ability to cut them to exact specifications.
Colored gemstones can be made via several methods, all of which leave behind identifiable markers, namely unusual inclusions or growth patterns. Illustrating her point, she singled out flux-grown gems that can contain fragments of that flux and flame-fusion gems that often have curved striae. Both of these growing methods are very often recognizable by a gemologist working with standard tools of the trade.
“Natural colorless diamonds have no competition – there simply are no natural colorless gemstones with the level of brilliance and dispersion inherent in diamonds,” Mayerson said. “The most challenging task for all gemologists trying to separate natural from lab-grown diamonds is analyzing jewelry that features melee diamonds With clean, colorless, tiny diamonds set in jewelry, not only does the mounting often limit the gemologist’s view of the diamond for testing, but often the characteristics that help laboratories separate lab-grown from natural diamonds have been cut away, leaving little to no evidence of their origins.”
As a result, multiple advanced testing machines are required to check other properties of the diamonds in question. Also required are gemologists with extensive experience and specific subject matter knowledge to properly interpret the data from the advanced testing machines.
Specifically, Mayerson said that the laboratory gemologists at GSI use a variety of advanced spectroscopic instruments to make the separation. For most diamonds, there is no magic black box that separates natural diamonds from lab-grown. Some pieces received by the lab are mounted with hundreds of tiny diamonds weighing as little as 0.003 carats. To resolve this challenge, GSI works directly with advanced testing machine manufacturers to create specialized machines that can accommodate jewelry items.
Read the Article on IGS: https://www.gemsociety.org/article/why-synthetic-diamonds-are-not-like-synthetic-colored-gemstones
