The move, expected to take effect later this year, signals a clearer division between natural and lab-created stones.

Instead of detailed grading reports, lab-grown diamonds submitted to GIA will be classified under simplified quality tiers—“premium” or “standard”—or may not be graded at all if they do not meet minimum standards. The change reflects GIA’s acknowledgment that the traditional 4Cs, developed to highlight the complex and unique attributes of natural diamonds, are less relevant for lab-grown stones, which tend to fall within a narrow range of quality.

This move is seen as a formal step toward reinforcing the distinction between natural and synthetic diamonds—a distinction that many in the industry have long emphasized. Natural diamonds, formed over billions of years under the Earth’s surface, are valued for their rarity and unique characteristics. In contrast, lab-grown diamonds are created through controlled processes like High-Pressure High-Temperature (HPHT) and Chemical Vapor Deposition (CVD), allowing for mass production and aesthetic replication.

The 4Cs grading system was originally developed by GIA in the mid-20th century to help consumers assess and compare natural diamonds. Industry experts argue that applying the same system to lab-grown stones has contributed to consumer confusion, blurring the lines between the two.

By redefining how lab-grown diamonds are assessed, GIA is aiming to restore clarity in the marketplace and uphold the unique identity and value of natural diamonds—an important move in a market where both products continue to coexist but serve different consumer needs.