Persistent reports that large amounts of synthetic lab grown diamonds are being mixed with natural diamonds in parcels of melee and pointers.
After more than 600 synthetic colorless diamonds were submitted to the International Gemological Institute without disclosure, the lab is warning the trade about the possibility of more undisclosed stones on the market.
According to an IGI Trade Alert issued last week, the diamonds were grown by the CVD process and submitted to the lab’s facilities in Antwerp and Mumbai. The dealer submitting the stones had no idea they were man-made, and paid prices equivalent to natural diamonds, IGI says.
“I believe there are other undisclosed colorless synthetic diamonds out there,” IGI Worldwide co-CEO Roland Lorie tells JCK. “But we just don’t know how many. I don’t think the volume is huge. You just wonder how this parcel got out there, and how many else are left.”
Lorie adds: “In the past we have received two stones here, three stones there. But it’s always been in small volumes. When you get so many stones, it’s an entirely different story.”
The IGI alert was followed by an alert issued by De Beers’ Diamond Trading Company, which noted that undisclosed stones had also appeared at the National Gems & Jewellery Technology Administrative Centre (NGTC) lab in China.
The stones in question were mostly 0.30 ct to 0.70 cts., F to J colour, VVS to VS clarity, and internal characteristics included feathers, pinpoints, and small dark crystals. Polish, symmetry, and cut were either “excellent” or “very good,” with bruted or faceted girdles. All stones were Type IIa, characteristic of CVD synthetics.