GIA to revise laboratory-grown diamond services from October

The Gemological Institute of America (GIA) will introduce updated evaluation services for D-to-Z laboratory-grown diamonds from 1 October, replacing its existing system.

The new service, called the Laboratory-Grown Diamond Quality Assessment, will use descriptive terms rather than the grading nomenclature developed for natural diamonds. 

Stones will be described as either “Premium” or “Standard” based on their overall clarity, colour and cut. 

Diamonds that do not meet the minimum criteria for “Standard” will not receive an assessment.

Additionally, diamonds classified as “Premium” must achieve the highest clarity, colour and cut grades, including very, very slightly included clarity, D colour and excellent cut (for round brilliants). 

Stones meeting slightly lower thresholds, such as E-to-J colour and very good cut or polish, will fall into the “Standard” category.

The fee for the new service will be $15 (£11.16) per carat, with a minimum of $15 (£11.16). Stones not meeting assessment criteria will be subject to a $5 (£3.72) evaluation fee. 

The minimum size for submissions is 0.15 carats. Each assessed diamond will be laser inscribed “Laboratory-Grown” with its quality assessment number, and accompanied by a printed report.

Pritesh Patel, GIA president and chief executive, said: “Using descriptive terms for the quality of laboratory-grown diamonds is appropriate as most fall into a very narrow range of colour and clarity. Because of that, GIA will no longer use the nomenclature created for natural diamonds to describe what is a manufactured product.”