A synthetic round diamond was recently submitted to GIA’s gem lab with a fake inscription matching a natural diamond report.

According to a GIA Lab Note, its Carlsbad laboratory recently took in a 1.76 ct. F VS1 excellent cut round bearing an inscription on the girdle for a GIA report issued in 2015, which was meant for a  1.74 ct. D VVS1 natural untreated stone.

GIA’s screening process, however, determined that the stone needed additional testing. Further research showed the stone to be a HPHT grown synthetic diamond.


Careful examination of the report number inscribed on the synthetic diamond revealed a font different from the one used by GIA, proving that it was not an authentic inscription.

“While most synthetic diamonds that come to the laboratory are properly disclosed, some are submitted out of concern that a stone presented as natural might be synthetic,” said note authors Christopher M. Breeding and Troy Ardon. “Rarely do we encounter the type of blatant fraud described here “We believe the submitting client noticed inconsistencies with the GIA report information and sent it to the lab for an updated report.”

This is not the first time the trade has seen this kind of episode. Last year man-made diamonds sold with ‘natural reports’ were discovered on Asian website Alibaba.


  1. I said it over 15 years ago, when they start making good white synthetic diamonds, the global diamond market could be de-stabilised, and the public trust in diamonds undermined. The bigger problem will come with 2nd hand made up jewellery where assessment become more difficult. Thank heavens that new gemmological technologies are helping to some extent.
    This could lead to a need for many more licenced gemmological labs to be involved with every sale and purchase of diamond set jewellery !