The Gemological Institute of America recently identified a 5.01 ct. radiant-cut pink-orange lab-grown diamond (pictured) that came into its lab—and is now describing it as “the most remarkable CVD synthetic diamond GIA has tested so far.”

“Natural diamonds with intense pink-orange color are very rare, particularly in large sizes,” said the lab note, which appeared in the summer 2018 edition of GIA journal, Gems & Gemology, coauthored by GIA director of research and development Wuyi Wang and executive vice president and chief laboratory and research officer Tom Moses.

But this particular diamond was notable for evidencing some “outstanding gemological features,” the note continued—including its size, clarity (which it calls equivalent to SI), and color, which was evenly distributed throughout the stone.

The lab note further added that based on the diamond’s spectroscopic features, it did not appear to have been treated by HPHT annealing, though “heating to a moderate temperature could not be entirely ruled out.” (The company that submitted the stone, Unique Lab Grown Diamond, confirms it was heated at a moderate temperature.)

Unique Lab Grown Diamond, based in New York City and Mumbai, India, displayed the stone at the lab-grown pavilion at this year’s JCK Las Vegas, says company spokesperson Shardul Vashi. He adds that, to his knowledge, the stone is the largest pink created by the CVD process and may even top any lab-grown pink that has been created by the HPHT process as well.

“We have many diamonds of this color but not this size,” he says. “The second largest diamond we have is a round 3.23 ct. fancy light pink, which is International Gemological Institute certified.”

CVD stands for chemical vapor deposition, and it is one of the two most common methods used to produce synthetics. The other commonly used method is HPHT, which stands for high-temperature, high-pressure.

(Photo courtesy of Unique Lab Grown Diamond)

Rob Bates

JCK News Director