GIA has spoken: Your lab diamonds are not the same as the natural ones

In the world of gemology, few names command as much respect as the Gemological Institute of America (GIA). Since its founding in 1931, GIA has been the gold standard in diamond grading, setting the benchmarks that define value, beauty, and rarity. Now, in a landmark move announced in early June, GIA is once again reshaping the diamond industry — this time by fundamentally altering how lab-grown diamonds are assessed.

End of an era

The 4Cs — Cut, Colour, Clarity, and Carat — have been the cornerstone of diamond evaluation since GIA formally introduced the rigorous system in 1953, a concept pioneered by its founder, Robert Shipley, in the 1940s. For decades, this universal language has helped consumers understand the quality and nuances of natural diamonds, ensuring transparency and trust in the luxury market.

However, the rise of lab-grown diamonds has disrupted the industry. With their near-identical optical properties and significantly lower prices, these man-made stones have flooded the market, causing confusion among buyers and eroding the value perception of natural diamonds.

In response, GIA has taken a bold step: Beginning at the end of 2025, lab-grown diamonds submitted to GIA will no longer be graded using the 4Cs system. Instead, they will receive simplified descriptors: ”Premium,” “Standard,” or no grade at all if the quality is subpar.

Why this change matters

The decision is not merely a shift in terminology — it is a strategic effort to reinforce the fundamental differences between natural and lab-grown diamonds. As a non-profit organisation, GIA finds it necessary to offer consumers enhanced clarity on both types of gemstones, including their formation processes, physical characteristics, and market values.

Explains Tom Moses, GIA executive vice president and chief laboratory and research officer, “More than 95 per cent of lab-grown diamonds entering the market fall into a very narrow range of colour 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 colour and clarity of natural diamonds.”

Natural diamonds, formed over billions of years under extreme pressure and heat, carry unique inclusions, growth patterns, and hues — each one a singular work of art from Mother Nature. Their rarity and emotional significance have made them enduring symbols of love, legacy, and investment. For instance, of all diamonds submitted to the GIA annually, no more than 3 per cent are classified as coloured diamonds — with less than 5 per cent of that graded as pink.

Lab-grown diamonds, on the other hand, are produced in weeks using High-Pressure High-Temperature (HPHT) or Chemical Vapor Deposition (CVD) methods. While chemically identical, their industrial origins mean they lack the scarcity, geological history, and emotional resonance of natural diamonds.

Consumer trust and market integrity

The diamond industry has faced growing challenges as some lab-grown diamond sellers have employed misleading marketing tactics, using terms like “sustainable” and “identical to natural diamonds” without proper context.

While there are indeed top lab diamond producers, such as French brand Courbet, that hold themselves to the highest of production, sustainability, and marketing standards, most of this segment of the diamond industry is shrouded in secrecy.

GIA’s new grading system ensures clarity and transparency, empowering consumers to make informed choices. By decoupling the grading standards for natural and lab-grown diamonds, GIA reaffirms that the two are not interchangeable — neither in origin nor in value. This move is expected to stabilise the historic natural diamond market, reinforcing its prestige while allowing lab-grown upstarts to occupy their own distinct space.