HRD Antwerp is now grading lab-grown diamonds using the same color and clarity scales it applies to natural stones, the laboratory confirmed to National Jeweler.
In its new man-made grading reports, which launched during the week of 4th March, HRD Antwerp has migrated from having just five color grades—colorless, near colorless, faint, very light and light—to the same 13 that it uses for natural diamonds—D to M, plus N-O, P-R and S-Z.
The Belgian grading lab is also switching from five clarity grades—free of inclusions (FI) to included (I)—to the same 10 applied to mined diamonds, starting with loupe clean (LC) and ranging to P3 (pique 3).
“Our aim is to serve the industry as a whole, from rough to consumers. We identified a need for better transparency and support concerning the new complications [meaning undisclosed mixing of lab-grown diamonds with natural] that arise with lab-grown diamonds,” the lab said in a statement to National Jeweler. “For this reason, we developed the set of measures explained above. The certification is just one piece of the complete puzzle of services we provide to enhance trust and transparency.”
HRD Antwerp has been issuing grading reports for lab-grown diamonds since 2013.
In the fall, it plans to add a report for finished pieces of jewelry set with man-made stones (the lab already issues reports for jewelry set with natural stones.)
The issue of how to grade lab-grown diamonds is a source of disagreement in the trade.
In October 2016, National Jeweler talked to Tom Moses, the Gemological Institute of America’s executive vice president and chief laboratory and research officer, about why the GIA uses a limited, less specific grading scale in its “Synthetic Diamond Reports” instead of the four Cs.
In the interview, Moses said that generally speaking, lab-grown diamonds are nitrogen-poor, so they are going to be of high color and clarity and not exhibit the same range of color and clarity as mined diamonds.