GIA (Gemological Institute of America) is seeing an
increase in the number of laboratory-grown diamonds submitted for update or verification services
with counterfeit inscriptions referencing GIA natural diamond reports. The majority of the newlysubmitted
laboratory-grown diamonds have higher clarities and their measurements and weights
were almost identical to the GIA reports referenced by the counterfeit inscriptions.
“This unfortunate situation demonstrates why it is important, especially in any transaction where
the buyer does not have a trusted relationship with the seller, to have the diamond grading report
updated before completing a purchase,” said Tom Moses, GIA executive vice president and chief
laboratory and research officer.
This most recent example, submitted in Antwerp, of a laboratory-grown diamond with a
counterfeit inscription highlights how close the man-made stone's measurements are to the
information on the original report. The report that accompanied the stone submitted for an update
was for a 3.078 carat, 9.33 - 9.38 x 5.74 mm, Internally Flawless, G, natural diamond with triple
excellent make. The newly-submitted stone was a 3.075 carat laboratory-grown diamond
measuring 9.39 - 9.41 x 5.76 mm, VVS2, H, with a triple excellent make. At first glance, the
natural and laboratory-grown diamonds described above are almost identical; the measurements
were within just hundredths of millimeters of each other.
Consistent with GIA's mission to protect consumers and ensure their trust in gems and jewelry,
when GIA encounters these cases, the Institute overwrites the counterfeit inscription, inscribes a
newly issued report number and "Laboratory-Grown" on the girdle of the diamond.
In February 2021, GIA reported a similar incident of a number of treated natural diamonds
submitted for update or verification services with counterfeit report number inscriptions.