Lab Grades Its Largest CVD Diamond

RAPAPORT... The International Gemological Institute's (IGI) Hong Kong laboratory has graded a 12.75-carat synthetic diamond, the largest chemical vapor deposition (CVD) stone it has ever received.The lab-grown stone, cut from a 46.20-carat rough, has F color and VVS2 clarity, and is type IIa, the IGI said Monday. It was created by Shanghai Zhengshi Technology Co., which claims it is the largest lab-grown diamond ever produced."A laboratory-grown diamond of this carat weight, with such a high clarity and color grade, is a remarkable achievement in CVD-cultivated diamond technology," noted IGI Hong Kong managing director Bob Van Es. Last month, IGI reported it had graded a 115.65-carat, black synthetic diamond created using High Pressure-High Temperature (HPHT). That stone ranked as the largest lab-grown diamond of its color, IGI added.Image: The 12.75-carat CVD diamond. (International Gemological Institute)