GIA not to use 4C system to grade lab-grown diamonds

GIA to simplify grading system for lab-grown diamonds, ensuring clear distinction from natural diamonds for consumers.

The Gemological Institute of America (GIA), considered the world’s foremost authority on gemmology, said later this year, it will start using descriptive terms to characterise the quality of laboratory-grown diamonds and no longer use colour and clarity nomenclature it had developed for natural diamonds and been in use since 1953. 

It means GIA will drop its traditional 4Cs (Colour, Clarity, Cut & Carat Weight) diamond grading system for lab-grown diamonds to ensure clear demarcation between natural and man-made diamonds. Later this year, lab-grown diamonds handed over to GIA will receive simplified descriptors—categorised broadly as either “premium” or “standard”— or no grade at all if the quality is subpar.

The institute said it would continue to accept laboratory-grown diamonds for evaluation and identification.

“Similar to other man-made gem materials, we anticipate the continued acceptance and popularity of laboratory-grown diamonds,” said Tom Moses, GIA executive vice-president and chief laboratory and research officer in a statement. 

Amit Pratihari, Managing Director, De Beers India said, “GIA’s decision is a timely and important move that brings much-needed clarity to consumers. 

“It reinforces the fundamental differences between natural diamonds and lab-grown — not just in origin, but in emotional and enduring value. We have always maintained that natural diamonds are rare, billions of years old, and deeply symbolic — a fact that resonates strongly with Indian consumers,” he said.

Kirit Bhansali, Chairman, Gem & Jewellery Export Promotion Council (GJEPC) said, “This change will help eliminate confusion by clearly distinguishing how lab-grown diamonds are assessed, separate from the standards developed for natural diamonds.”