GIA Shifts Focus: Moving Away from Specific Clarity and Color Grades for Lab-Grown Diamonds in Favor of Descriptive Terminology

The Gemological Institute of America (GIA) is updating its reporting approach for lab-grown diamonds once again. This time, the change marks a return to a simpler classification system. Starting later this year, GIA will cease using the detailed color and clarity grades it traditionally applied to natural diamonds when assessing lab-created stones. Instead, the process will involve two steps: first, confirming that the gemstone is indeed lab-grown, and second, evaluating its color, clarity, and overall finish to categorize it as either “premium” or “standard.” If a lab-grown diamond does not meet the minimum quality standards, it will not be assigned a category.

These CVD-grown diamonds vary from 9.52 to 12.06 carats. Their color ranges from E to G and their clarity from VS2 to SI1. Large laboratory-grown diamonds like these have become more common in recent years.

The decision stems from significant narrowing of the color and clarity spectrum observed in lab-grown diamonds, thanks to ongoing advancements in diamond cultivation technology. GIA explained that this adjustment aims to clarify the differences between natural and lab-grown diamonds, ensuring consumers can make better-informed decisions—recognizing the distinct origins of each type.

Since 2022, data indicates that 95% of lab-grown diamonds submitted for grading are essentially colorless, earning grades of D, E, or F, while approximately 98% have clarity grades of VS1 or higher. GIA’s Executive Vice President and Chief Laboratory and Research Officer, Tom Moses, commented on the change, stating, “As with other man-made gemstones, we expect the continued growth and acceptance of laboratory-grown diamonds. Because over 95% of these stones in the market fall within a very narrow range of color and clarity, describing them with the traditional grading scale used for natural diamonds no longer makes sense.”

The CVD diamond plate on the left was created at a GIA facility for research purposes. On the right is a 10.02 carat, E color, VS1 clarity HPHT grown emerald cut diamond. Its size and quality show just how far laboratory-grown diamond technology has come in recent decades.

Moses’ insights build on his remarks from a 2016 interview, in which he explained GIA’s rationale behind grading lab-grown diamonds differently. At that time, GIA used broader terms such as “colorless” for D-F range stones and “near colorless” for G-I stones. The clarity grades were limited to four categories—VVS, VS, SI, and I—compared to eleven grades used for natural diamonds. Moses emphasized that this simplified grading approach was appropriate because laboratory-grown stones generally do not exhibit the full range of color and clarity found in mined diamonds. He also pointed out that GIA’s original grading system, established in the 1940s, was designed for natural diamonds, which have a much wider variability, making it less applicable to the more uniform qualities seen in lab-created gems.

For more information regarding lab-grown diamonds, please visit this article from GIA. https://www.gia.edu/gia-news-research/gems-gemology-summary-latest-research-lab-grown-diamonds