Coloured lab-grown diamond infiltration on the rise: GSI

by Tamanna Bhasin | February 16, 2024 1:08 pm

Gemological Science International (GSI) has reported a concerning rise in undisclosed laboratory-grown brown, yellow, and pink diamonds within the natural diamond supply chain.

The observation highlights a key problem in the industry. While measures have been taken to isolate white lab-grown diamonds, coloured lab-grown diamonds continue to pose an issue. Since most screening machines are not designed to identify and react to coloured synthetic diamonds, they are more likely to pass for natural.

As per JCK[1], co-founder and president of GIS, Debbie Azar, notes, “There can be a huge value difference between a natural and a synthetic, especially in coloured diamonds. 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 jewellery, I hope they’ll take the same steps in coloured diamonds.”

Many of the coloured lab-grown diamonds GIS has detected have been Type IIa, mounted in jewellery, and ranging in size from melee to one carat. Azar explains these smaller diamonds, placed in mountings, are even harder to detect.

The identified diamonds had also been designed specifically to mimic natural gemstones, cut with intentional flaws such as fractures, pinpoint clouds, and brown grain lines. “With lab-grown diamonds, they generally have enough material to polish it up nice,” says Azar. “But, they didn’t, and we believe they did that to mimic natural diamonds.”

GIS is attempting to track the origin of the lab-grown diamonds. Currently, the lab suspects they were manufactured in India, though the evidence is not yet conclusive.

Source URL: https://www.jewellerybusiness.com/news/gemmological-grading-lab-reports-rise-in-lab-grown-diamond-infiltration/

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