Press Release

GIA Examines 34.59 Carat CVD Laboratory-Grown Diamond

The GIA laboratory in Hong Kong recently evaluated the largest chemical vapor deposition (CVD) laboratory-grown diamond seen by the Institute.
This 34.59 ct CVD-grown diamond (24.94 × 13.95 × 9.39 mm), produced by the Ethereal Green Diamond in India, is the largest seen by GIA. Photo by Johnny (Chak Wan) Leung (GIA).

More than twice the size of the then-largest CVD-grown diamond, seen in 2022

CARLSBAD, Calif. – May 4, 2023 – The GIA (Gemological Institute of America) laboratory in Hong Kong recently evaluated the largest chemical vapor deposition (CVD) laboratory-grown diamond seen by the Institute. Produced by Ethereal Green Diamond in India, the 34.59 ct, 24.94 × 13.95 × 9.39 mm, emerald-cut laboratory-grown diamond was evaluated as VS2, G color. The size of the largest CVD diamond seen by GIA increased by 111% since the Institute reported on a then record-sized 16.41 ct CVD laboratory-grown diamond in 2022.
Gems & Gemology (G&G), GIA’s quarterly professional journal, recently published an online research note that includes all observations and spectroscopic features of this latest record CVD-grown diamond. The research note will appear in the Summer 2023 print edition of the journal.
“This more than two-fold increase in size within one year is an impressive technical achievement in CVD diamond growth,” said Tom Moses, GIA executive vice president and chief laboratory and research officer. “With such production improvements, correct identification and disclosure are critical to maintaining consumer trust; this is another example of why GIA devotes significant resources and research to protect consumer confidence.”
This 34.59 ct CVD laboratory-grown diamond has minute features that resulted in it being evaluated as VS2 for clarity. Researchers found small black graphite inclusions, some along the inside of the body, while others formed clusters of clouds between growth layers. Microscopic observation showed a weak “oily” or wavy graining looking through the table, a feature sometimes seen in CVD laboratory-grown diamonds.

About GIA

An independent nonprofit organization, GIA (Gemological Institute of America), established in 1931, is recognized as the world’s foremost authority in gemology. GIA invented the famous 4Cs of Color, Clarity, Cut and Carat Weight and, in 1953, created the International Diamond Grading System™ which is recognized around the world as the standard for diamond quality.

Through research, education, gemological laboratory services and instrument development, the Institute is dedicated to ensuring the public trust in gems and jewelry by upholding the highest standards of integrity, academics, science and professionalism.