GIA recently examined a world-record lab-grown diamond produced by the chemical vapor deposition (CVD) method, a 16.41-carat princess-cut diamond from Shanghai Zhengshi Technology Co Ltd. 

According to the institute, detailed spectroscopic readings confirmed there was no post-growth treatment to improve the colour of the G-colour, VVS2-clarity lab-grown diamond.

GIA Vice President of Research and Development Dr. Wuyi Wang, who examined the new record-sized CVD diamond, said, “The first CVD diamond I examined in 2003 was a 0.23-carat pear shape, with clear brown colour. This 16.41-carat laboratory-grown diamond demonstrates the advances in CVD growth technology. This achievement has important implications for the many scientific and industrial applications for high-quality laboratory-grown diamonds.”

GIA experts graded the diamond using the institute’s standard rigorous process for laboratory-grown diamonds, issuing GIA Laboratory-Grown Diamond Report number 2225246686.

In terms of CVD growth, the 16.41-carat stone breaks the record previously held by a 14.6-carat emerald-cut lab-grown F-colour diamond of VS2 clarity produced in India last year. The largest lab-grown diamond of any kind tested by GIA is a cushion-cut, 20.23-carat fancy vivid yellowish orange diamond of VS2 clarity created by the HPHT method in 2019.