12.75-carat Diamond is Largest Ever CVD Lab-Grown, says IGI

(IDEX Online) - A Chinese manufacturer has produced the largest polished CVD lab-grown diamond ever certified by IGI Hong Kong - weighing 12.75 carats.

The Type IIa diamond, graded as F color and VVS2 clarity, (pictured) was cut from a 46.20-carat rough CVD stone grown by the Shanghai Zhengshi Technology.

IGI gemologists said it had exceptional chemical purity and transparency, triple-excellent marks in cut-quality and finish, and no signs of any post-growth treatments.

Bob Van Es, managing director of IGI Hong Kong said: "A laboratory grown diamond of this carat weight, with such a high clarity and color grade is a remarkable achievement in the area of CVD cultivated diamond technology.

Shanghai Zhengshi Technology claimed it was the largest CVD laboratory-grown diamond ever produced.  Last month IGI graded a world record 115.65-carat black diamond which was produced by HPHT.