While imitation diamonds such as cubic zirconia (or CZ) have always been a part of the jewelry business, synthetic diamonds—which are chemically identical to mined diamonds but formed in a lab instead of deep underground—are becoming more common.

“Man-made diamonds—synthetics—have essentially the same optical, physical, and chemical properties as their natural counterparts,” says gem expert Bill Boyajian, who is a graduate gemologist, former president of the GIA, and founder and CEO of Bill Boyajian & Associates. “They are diamonds, yet they are made by man.”

Although the physical and chemical properties are the same, U.S. federal regulators require lab-created diamonds to be labeled with terms such as synthetic, laboratory-grown, laboratory-created, or man-made. Synthetic diamonds also possess a property known as type II, which indicates the absence of nitrogen. This makes these stones crystal clear, without any yellowish tinge, and also helps experts identify them.

Creating diamonds in a lab has its roots in industrial production: Companies that make everything from semiconductors to drill bits don’t need gem-quality stones. These lab-created stones are 20 to 30 percent less expensive than their mined counterparts, and improvements to the production process in recent years have made these stones easier to make. It then became a short leap for some producers to consider the gem trade.

“Though it has taken decades to perfect their gem-quality production, they are now a factor to deal with for the natural diamond trade and an emerging alternative for the diamond-buying public,” Boyajian says.

JCK