IGI recently analyzed a 6.01 carat pear-cut gemstone with a grading report number inscribed on the girdle corresponding to a natural diamond, but concluded that it was a laboratory grown diamond. That lab grown stone’s carat weight, physical spread, and primary qualities were a close match with the natural diamond’s online grading data.

“Everyone in our industry must be vigilant,” stated CEO Tehmasp Printer. “IGI pioneered the grading of lab grown diamonds nearly two decades ago for the purpose of clear separation from natural stones. As attempted fraud increases, the need for ongoing verification is a necessary step to protect consumers from purchasing misrepresented gems and jewelry.”

Subtle Discrepancies: While the main qualities of the stone paralleled the online report data the inscription pointed to, IGI’s gemologists soon deduced that it was lab created. Photoluminescence spectroscopy revealed a doublet at 737 nm due to Silicone Vacancy (SiV) defects, indicating laboratory growth using the Chemical Vapor Deposition (CVD) process.

This was further supported by microscopy, which showed a carbon inclusion in place of the feather indicated online, and a cloud, which would result in a lower clarity grade from IGI. A slight depth mismatch was also revealed. Such discrepancies could go unnoticed outside of a laboratory, particularly once the stone is set into a piece of jewelry.

Alert Issued: The client submitted the stone for screening, to determine whether it was natural or not. When the fraudulent inscription was uncovered IGI issued an alert to trade media with details supporting images. Additionally, per IGI policy, a laser-inscription with the LG prefix was added to the stone to clearly identify it as laboratory grown. A written statement was also issued to the client, so they may take it forward.

The alert has been shared by trade media platforms, including IDEX, InStore Magazine, National Jeweler, Professional Jeweler, and Rapaport, among others. This discovery comes on the heels of other industry alerts stating that lab grown diamonds are being sold as natural.

“IGI protects jewelry buyers and sellers from fraud with thorough screening and grading of gemstones and finished jewelry at all 29 of our worldwide locations,” Mr. Printer added. “A current grading report ensures accuracy, confidence, and peace of mind for professionals and consumers alike.”