IGI Grades Largest Polished Lab-Grown

RAPAPORT… The International Gemological Institute (IGI) has graded a 27-carat lab-grown stone that it claims is the world’s largest polished synthetic diamond.

Indian lab-grown company Greenlab created the marquise step-cut, 27.27-carat diamond, named Om, IGI said Wednesday. The stone, which has no color enhancement, was grown using chemical vapor deposition (CVD).

Along with Om, the IGI graded two additional lab-grown stones submitted by Greenlab, including Shivaya, an emerald-cut diamond weighing 20.24 carats, and Namah, a pear rose-cut, 15.16-carat polished. Greenlab plans to display the diamonds at the JCK Las Vegas show, it noted.

Previously, the largest known polished CVD diamond was a princess-cut, 16.41-carat, G-color, VVS2-clarity stone created by Shanghai Zhengshi Technology. The Gemological Institute of America (GIA) graded the stone in January.

At the time, the largest polished lab-grown diamond of any sort the GIA had examined was a cushion-cut, 20.23-carat, fancy-vivid-yellowish-orange, VS2-clarity diamond created using the High Pressure-High Temperature (HPHT) method in 2019.

Image: The three lab-grown diamonds from Greenlab. (International Gemological Institute)