Editor’s Note
The Gemological Institute of America (GIA) has introduced new grading criteria for lab-grown diamonds, effective October 1. The updated system will classify synthetics as “Premium” or “Standard” based on clarity, color, and cut, moving away from its traditional nomenclature.
The Gemological Institute of America (GIA) has announced the details of its new grading criteria for lab-grown diamonds.
The institute — which will start issuing certificates with the updated format on October 1 — will use the terms “Premium” and “Standard” to describe synthetics, rather than the usual GIA nomenclature, it said Wednesday.
The clarity, color and cut will determine which of those new ratings the stone receives in its GIA Laboratory-Grown Diamond Quality Assessment, which the institute first revealed in June.
To earn the Premium label, lab-grown diamonds must be D-color and have a minimum clarity of VVS, as well as excellent polish and symmetry; round brilliant stones will also require an excellent cut grade. The Standard category is for stones with a color range of E to J and VS clarity. They must also have a polish rating of “very good,” plus a symmetry of “good” for fancy shapes and “very good” for round brilliants — which should bear the same rating for cut grade.
Synthetics that have a combination of Premium and Standard criteria will be graded as Standard, the GIA clarified.
The GIA will charge $15 per carat for each report, with a minimum fee of $15 — meaning a certificate for a 5-carat diamond would cost $75, while one for a 0.50-carat stone would be $15. The institute will only accept synthetics of 0.15 carats and above.
Each stone that meets the lab’s criteria for a report will have its girdle laser-inscribed with the term “laboratory-grown” and a GIA quality-assessment number. The institute will then return the diamond with a printed document containing the results. Stones that don’t meet the criteria for a Standard grade will not receive a report, according to the GIA; the lab will send them back, and the submitter will still need to pay a $5 evaluation fee.
The current GIA reports for D to Z lab-grown diamonds will be available until September 30.
Image: The new lab-grown quality assessment report. (Gemological Institute of America)