Grading lab Gemological Science International (GSI) has seen an increase in undisclosed laboratory-grown brown, yellow, and pink diamonds infiltrating the natural diamond supply chain.
The undisclosed synthetics are often sold mounted, mixed in with natural colored diamonds in jewelry, says Debbie Azar, cofounder and president of the New York City–based lab.
She notes that “most screening machines are not built to react to synthetic colored lab-grown diamonds,” so colored diamonds are less likely to be caught than white ones.
“There can be a huge value difference between a natural and a synthetic, especially in colored diamonds,” says Azar. “I hope the industry will be aware of this and will do what it can, and the retailers will be vigilant. The actions and steps the industry has taken regarding white diamonds in finished jewelry, I hope they’ll take the same steps in colored diamonds.”
Many of the undisclosed colored lab-growns detected by GSI were Type IIa. All were mounted in jewelry, and they varied in size from melee to one carat.
“The smaller ones are going into mountings, which makes them harder to detect,” Azar says.
In some instances, the lab-grown colored diamonds were intentionally cut with flaws similar to those seen in natural diamonds, such as severe fractures, pinpoint clouds, or distinct brown grain lines.
“With lab-grown diamonds, they generally have enough material to polish it up nice,” she says. “But they didn’t, and we believe they did that to mimic natural diamonds.”
Azar suspects the undisclosed colored lab-growns originated in India, but says she can’t be sure. “We are doing some research, to see if we can track them back,” she says.
Federal Trade Commission guidelines require that non-mined diamonds be labeled with certain language, such as “lab-grown” or “lab-created,” that makes it clear the diamonds are not natural.
Top: One of the undisclosed lab-growns spotted by GSI (photo courtesy of GSI)
