Editor’s Note
This article highlights a sophisticated case of diamond fraud, where a lab-grown stone was inscribed with a report number for a natural diamond. It underscores the critical importance of advanced gemological testing and vigilance in the trade.
The International Gemological Institute (IGI), the world’s largest independent gemological laboratory, recently analyzed a 6.01-carat pear-shaped gemstone with a laser inscription corresponding to a natural diamond report number. However, the analysis concluded it was laboratory-grown.
While the stone’s main characteristics matched the online report data referenced by the inscription, IGI gemologists soon determined it was lab-created. Photoluminescence spectroscopy revealed a doublet at 737 nm due to silicon vacancy defects (SiV), indicating growth using the Chemical Vapor Deposition (CVD) method. This was further supported by microscopy, which showed a carbon inclusion and a cloud instead of the feather mentioned in the online report, leading to a lower IGI clarity grade. A slight depth incongruity was also noted. Such discrepancies can go unnoticed outside a laboratory, especially once the stone is set in jewelry.
IGI CEO Tehmasp Printer issued this warning, emphasizing the industry’s need for vigilance.
