On Oct. 1, GIA will roll out its Laboratory-Grown Diamond Quality Assessment (pictured), which will include the new “premium” or “standard” designation for lab-grown diamonds. Current laboratory services for D-to-Z lab-grown diamonds will be available until Sept. 30, GIA noted. (Photo courtesy of the Gemological Institute of America)
Carlsbad, Calif.—After announcing plans to change the way it grades lab-grown diamonds (again), the Gemological Institute of America shared details on its new approach Tuesday.
Beginning Oct. 1, the lab will replace its digital-only lab-grown diamond grading reports, which evaluate the stones using the same color and clarity scale applied to natural diamonds, with a printed and much more general document called the GIA Laboratory-Grown Diamond Quality Assessment.
The assessment will be available only for lab-grown diamonds of a certain size (0.15 carats and up) and quality, with each stone being classified as either “premium” or “standard.”
In its press release announcing the pending change, GIA outlined the criteria for the two classifications.
To be deemed “premium,” lab-grown diamonds must be: D color; VVS clarity or higher; have “excellent” polish and symmetry; and, for round brilliant-cut diamonds, a cut grade of “excellent.”
Lab-grown diamonds that meet any combination of the “premium” criteria described above and the following minimum criteria will be classified as “standard.”
Those minimum criteria are: E to J color; VS clarity; “very good” polish; “very good” symmetry (or “good” for fancy shapes); and, for round brilliants only, a “very good” cut grade.
Lab-grown diamonds that do not meet the minimum criteria will not receive an assessment, GIA said.