GIA Reverting to More General Terminology for Lab-Grown Diamonds

It will quit assigning the stones specific color and clarity grades in favor of applying “new descriptive terminology.”

Michelle Graff michelle.graff@nationaljeweler.com

Starting later this year, GIA will change its approach to lab-grown diamonds once again, abandoning the use of specific color and clarity grades for the stones in favor of assigning them to one of two categories, “premium” or “standard.”

Carlsbad, Calif.—The Gemological Institute of America is once again changing the reports it issues for lab-grown diamonds.

This time, the lab is going right back to where it started from, sort of.

On Monday, GIA announced that beginning later this year, it will quit using the color and clarity nomenclature it developed for natural diamonds in evaluating lab-grown diamonds.

Instead, the lab will, first, confirm that the submitted stone is a laboratory-grown diamond and then evaluate its color, clarity, and finish to determine if it falls into one of two categories: “premium” or “standard.”

If the lab-grown diamond fails to meet the minimum standard for quality, it will not receive a designation from GIA.

The lab said it is making the change in response to the dramatic compression in the range of color and clarity seen in lab-grown diamonds, a change that has come about as a result of continual improvements in diamond-growing technology in recent years.

It also noted that this revision will “help consumers understand the important differences in the two products’ origin, ensuring their confidence and enabling them to make informed and educated purchase decisions.”

GIA said that since 2022, 95 percent of the man-made diamonds submitted to the lab for grading have been colorless, meaning they would receive a grade of D, E, or F, while 98 percent received a clarity grade of VS1 or higher.

Executive Vice President and Chief Laboratory and Research Officer Tom Moses remarked, “Similar to other man-made gem materials, we anticipate the continued acceptance and popularity of laboratory-grown diamonds.

“More than 95 percent of laboratory-grown diamonds entering the market fall into a very narrow range of color and clarity. Because of that, it is no longer relevant for GIA to describe man-made diamonds using the nomenclature created for the continuum of color and clarity of natural diamonds.”

Moses’ remarks echo those he made in a 2016 interview with National Jeweler in which he explained the rationale behind GIA’s approach to grading lab-grown diamonds.

At that time, GIA used broader terms to describe lab-grown diamonds, calling stones in the D-F range “colorless” and those in the G-I range “near colorless,” and using only four clarity grades for the stones, VVS, VS, SI or I, compared with 11 for natural diamonds.

Moses said at the time that GIA chose to do it this way because lab-grown diamonds just aren’t going to have the same color and clarity range as mined diamonds.

To GIA, it didn’t make sense to apply its grading system—which Moses noted was developed for “normal mine run” in the 1940s, long before lab-grown diamonds were hitting the market in the quantities they are today—to man-made diamonds.