EditorsDec 13, 2021
Out & About: Watching De Beers Grow Diamonds in OregonLab-GrownFeb 02, 2022
GIA Examines Largest Known Diamond Grown Using CVD
It is more than 16 carats and G color/VVS2 clarity as grown, which is unusual in CVD diamonds.
This 16.41-carat princess-cut diamond produced using the CVD process measures 13.97 × 13.87 × 9.56 mm. Recently examined and graded by GIA, it is G color and VVS2 clarity. (Photo credit: Towfiq Ahmed)
Carlsbad, Calif.—Scientists at the Gemological Institute of America recently examined what is believed to be the largest diamond grown using the chemical-vapor deposition process, breaking a record set just last year.
The lab said Tuesday that the diamond is a 16.41-carat princess-cut stone grown by Shanghai Zhengshi Technology Co. Ltd.
The diamond had the “observable characteristics” of diamonds grown using the CVD process, including strong graining throughout—common in CVD stones—that gives the diamond a “wavy” appearance, as visible in the video below.
The lab said Tuesday that the diamond is a 16.41-carat princess-cut stone grown by Shanghai Zhengshi Technology Co. Ltd.
The diamond had the “observable characteristics” of diamonds grown using the CVD process, including strong graining throughout—common in CVD stones—that gives the diamond a “wavy” appearance, as visible in the video below.
The 16.41-carat lab-grown diamond is exceptional for another reason in addition to its size.
The diamond is G color and VVS2 clarity. GIA confirmed through detailed spectroscopic readings it was not treated post-growth to improve its color, which is unusual.
GIA Vice President of Research and Development Dr. Wuyi Wang, who examined the diamond, noted, “We have seen very few CVD diamonds of this quality.”
The 16.41-carat stone breaks the previous record for largest CVD diamond—a 14.60-carat emerald-cut stone produced in India and reported on by the International Gemological Institute in August 2021—by nearly two carats.
And it tops the record-holder before that, a 12.75-carat round brilliant lab-grown diamond, by almost four carats.
In article on the 16.41-carat lab-grown diamond authored by Wang and GIA research associates Stephanie Persaud and Elina Myagkay, the authors noted how the technology behind both CVD and high-pressure, high-temperature growth processes for diamonds has advanced significantly in the last two decades.
Wang noted in a GIA news release that he first examined a CVD diamond back in 2003, and it was less than half a carat, pear shaped and brown.
“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,” he said.
The article is available on the GIA’s website. It also will be published in an upcoming issue of Gems & Gemology, GIA’s quarterly research journal.
Related stories will be right here …
The diamond is G color and VVS2 clarity. GIA confirmed through detailed spectroscopic readings it was not treated post-growth to improve its color, which is unusual.
GIA Vice President of Research and Development Dr. Wuyi Wang, who examined the diamond, noted, “We have seen very few CVD diamonds of this quality.”
The 16.41-carat stone breaks the previous record for largest CVD diamond—a 14.60-carat emerald-cut stone produced in India and reported on by the International Gemological Institute in August 2021—by nearly two carats.
And it tops the record-holder before that, a 12.75-carat round brilliant lab-grown diamond, by almost four carats.
In article on the 16.41-carat lab-grown diamond authored by Wang and GIA research associates Stephanie Persaud and Elina Myagkay, the authors noted how the technology behind both CVD and high-pressure, high-temperature growth processes for diamonds has advanced significantly in the last two decades.
Wang noted in a GIA news release that he first examined a CVD diamond back in 2003, and it was less than half a carat, pear shaped and brown.
“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,” he said.
The article is available on the GIA’s website. It also will be published in an upcoming issue of Gems & Gemology, GIA’s quarterly research journal.
Another lab-grown diamond record was set recently, this one for a rough stone that was examined by IGI.
The lab said Jan. 20 that it recently analyzed a 150.42-carat blue diamond grown by biotech company Meylor Global using the HPHT method.
It is the heaviest rough lab-grown diamond on record, breaking the previous benchmark of 115 carats, also set by Meylor Global in September 2020.
The record for a faceted and colorless/near-colorless HPHT-grown diamond is 15.32 carats, tested by GIA in 2018.
The 150-carat diamond is gem-quality, IGI and Meylor confirmed, but Meylor hasn’t decided what it will do with the diamond.
IGI also noted that it recently examined another large lab-grown diamond from Meylor, this one a gray diamond weighing 141.58 carats.
Pictured at right is the 150.42-carat lab-grown rough diamond produced by Meylor Global, while the 141.58-carat stone is pictured at right.
Like GIA, IGI noted that the technology used to grow diamonds continues to improve.
“The acceleration of technology in the lab-grown diamond sector is significant,” said John Pollard, IGI’s recently appointed director of education.
“In addition to record-setting weights, they’re type IIb crystals, a semiconducting category associated with diamond-based electronics. At IGI, we’re seeing new benchmarks from the world’s most advanced producers in jewelry applications and beyond.”
More on Lab-Grown
The Latest
SurveysJul 01, 2026
Consumer Confidence Ticks Up in JuneFalling oil prices were a factor in the slight month-over-month improvement.
CollectionsJul 01, 2026
Rio Grande Launches First Finished Bridal CollectionThe new offering comprises more than 120 bridal and engagement ring styles with natural and lab-grown diamonds.
WatchesJul 01, 2026
Rolex Unveils Clock at Rockefeller CenterThe clock is part of the celebration for the soon-to-open Rolex headquarters on New York City’s Fifth Avenue.
Brought to you by
Wedding Band Trends 2026: Personalization Takes Center StageColored gemstones, artisan finishes, mixed metals, and meaningful details are shaping demand in bridal jewelry.
IndependentsJul 01, 2026
Kristen Cannon of Valobra Master Jewelers Dies at 49The public relations professional is remembered for her benevolent generosity and unwavering commitment to those around her.
Weekly QuizJul 01, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
WatchesJun 30, 2026
Pokémon Fans Will Want to Catch This New G-Shock WatchThe new watch commemorates Pokémon’s 30th anniversary.
MajorsJun 30, 2026
Saks Global Emerges From Bankruptcy With New NameThe luxury retailer is now called Exemplar Luxury Group.
Brought to you by
Building the Future of Jewelry Retail: DCA Expands Education, Leadership Development, and Workforce SolutionsDCA is preparing the next generation of professionals by supporting workforce development, leadership growth, and career advancement.
CollectionsJun 30, 2026
Jade Ruzzo’s New Collection Embodies the Art of Being a LadyThe “Lady” collection is a new take on old beauty standards with gemstone-adorned hair pins and combs, a compact mirror necklace, and more.
SourcingJun 30, 2026
Blue Nile Introduces Montana Sapphire CollectionThe new line is included in the e-tailer’s curation of jewelry celebrating America’s 250th anniversary.
GradingJun 30, 2026
AGS Opens 2026 Recertification ExamAll active members who earned their credential or designation before Dec. 1, 2025, are required to recertify.
CollectionsJun 29, 2026
Briony Raymond’s New Collection Is a ‘Carousel’ of Hard StonesThe new jewelry collection uses a colorful palette of onyx, malachite, tiger’s eye, mother-of-pearl, lapis, turquoise, and coral.
IndependentsJun 29, 2026
Look Inside Lee Michaels’ Revamped Mississippi FlagshipLee Michaels Fine Jewelry is celebrating 30 years in the Ridgeland, Mississippi community.
GradingJun 29, 2026
National Rarities Announces New Gemology ManagerSean Milliner has joined the company.
GradingJun 29, 2026
GIA to Open New London CampusClasses will begin in August at GIA’s new Canary Wharf location.
AuctionsJun 26, 2026
‘Hogback’ Diamond Ring Finds a New Home A ring set with “hogback” diamonds, an early stone cut dating to around the 16th century, sold for more than $20,000 at a U.K. auction.
CollectionsJun 26, 2026
Strength Is Sharpened Into Beauty in Kris Averi’s ‘Prism Thorn’ RingThe rainbow version of the ring, our Piece of the Week, features angel-cut, octahedral lab-grown sapphires designed to be worn as armor.
MajorsJun 26, 2026
Rembrandt Charms Debuts ‘Charms That Give Back’The new initiative donates a portion of the proceeds from select charms to charitable causes.
TrendsJun 26, 2026
Bernard James Celebrates Knicks’ Win with RingThe Brooklyn-based jeweler created a limited-edition version of its “Aura” eternity band, set with gemstones in the team’s colors.
SourcingJun 25, 2026
ICA Names Brandee Dallow as CEODallow will lead the International Colored Gemstone Association, effective July 6.
EditorsJun 25, 2026
Out & About: How Jewelers Mutual, SCAD Are Tackling the Bench Jeweler ShortageSenior Editor Lenore Fedow headed to Savannah to learn more about the 10-year, $10 million partnership between JM and the art school.
CollectionsJun 25, 2026
Mejuri Experiments With SteelIts new capsule jewelry collection features gold-finished stainless steel pieces designed for a maximalist look without a luxury price tag.
Events & AwardsJun 25, 2026
Watches & Wonders Announces 2027 DatesThe week-long event in Geneva is slated for April 2027.
SourcingJun 25, 2026
Annie Doresca, Mark Smelzer, Sara Yood Join Gem Legacy BoardThe three industry leaders bring financial, communications, and legal expertise to the nonprofit’s board of directors.
ColumnistsJun 24, 2026
The Revenue Hiding Between Your Counter and Your Online CartJewelers are missing out by not offering this one key add-on at the online point of sale, Emmanuel Raheb writes.
CollectionsJun 24, 2026
Greenwich St. Jewelers, Jewel Boxing’s Latest Drop Is On-TrendThe fourth collaborative collection from the retailer and jewelry content creator focuses on gemstone charms and strands of colorful beads.
Events & AwardsJun 24, 2026
AGTA Accepting Entries for Spectrum 2026This year’s AGTA Spectrum & Cutting Edge Awards will feature two new categories.
