The International Gemological Institute (IGI), the world’s largest independent gemological laboratory, recently analyzed a 6.01 carat pear-cut gemstone with a laser inscription corresponding to a natural diamond, but concluded it was laboratory grown. Submitted to IGI’s Tel Aviv location for verification, the lab grown stone’s carat weight, physical spread, and primary qualities were a close match with the natural diamond’s online 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.”
While the main qualities of the stone paralleled the GIA report data, IGI’s gemologists soon deduced that it was not a natural diamond. Photoluminescence spectroscopy revealed a doublet at 737 nm due to SiV defects, indicating laboratory growth using the Carbon Vapor Deposition (CVD) process. This was further supported by microscopy, which showed a carbon inclusion in place of the feather indicated by GIA, and a cloud, resulting 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.
IGI’s 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.”
To learn more visit www.igi.org.