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
WatchesMar 26, 2026
Q&A: Citizen Watch America President Jeffrey Cohen on Eco-Drive’s 50th AnniversaryCohen discusses the evolution of Citizen’s light-powered technology, the brand’s cross-generational appeal, and tariffs.
IndependentsMar 26, 2026
Peter Smith Pens Book on Human Behavior in Sales“Essentially Human: On Sales and Salespeople" reveals the underlying human traits and behaviors of the most successful sales professionals.
CollectionsMar 26, 2026
Lionheart Celebrates 13 Years of ‘Cassandane’The collection features symbols of love, luck, and light, based on the story of Queen Cassandane and Cyrus the Great of Persia.
Brought to you by
Protect Your Customers and Your BusinessYou deserve to know what you are selling–to protect your customers as well as your business and your reputation.
Events & AwardsMar 26, 2026
NAJA, Instappraise Introduce New ScholarshipIt’s the third scholarship to be launched as part of the partnership to help appraisers advance their professional credentials.
Weekly QuizMar 26, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
Events & AwardsMar 26, 2026
JA Still Accepting Entries for 2026 CASE AwardsThe deadline for entries in the jewelry design competition has been extended to April 3.
SourcingMar 25, 2026
Rob Bates Steps Down as JCK News Director After 28 years with JCK, the veteran industry journalist is launching his own publication on Substack called The Jewelry Wire.
Brought to you by
Is This You? Every Jeweler Has This Problem; We Have the Solution.Every jeweler faces the same challenge: helping customers protect what they love. Here’s the solution designed for today’s jewelry business.
GradingMar 25, 2026
New York’s Natural History Museum, Wiley To Build Minerals DatabaseWiley said the project will give scientists worldwide access to the American Museum of Natural’s History renowned mineral collection.
CollectionsMar 25, 2026
Boochier Turns Flower Friendship Bracelets Into Fine JewelryThe “Flower Puff” collection looks to beaded flower friendship bracelets from childhood, turning the silhouette into nostalgic fine jewelry.
Policies & IssuesMar 25, 2026
Community for Ethical Jewelry to Host Bench Jeweler Shortage WebinarSet for April 2, the webinar will discuss how the jewelry industry can address the workforce gap.
IndependentsMar 24, 2026
Lisa Bayer, Illustrator and Beloved Member of the Muse Family, Dies at 64Bayer, founder of Lisa Bayer Designs, is remembered as “a bright light in every room.”
AuctionsMar 24, 2026
White Diamonds Shine In Christie's Jewels Online SaleThe highest-grossing lot was a Tiffany & Co. ring set with a flawless, emerald-cut diamond of 10 carats.
SourcingMar 24, 2026
AGTA Solidifies Tucson Dates For 2027-2029The next three editions of AGTA GemFair Tucson will feature a five-day show that includes Sunday.
WatchesMar 24, 2026
Christie’s Names New Senior Specialist, WatchesFormer Sotheby’s executive Tom Heap has taken on the London-based role.
CrimeMar 23, 2026
NYPD Looking for 3 Jewelry Store Robbery SuspectsThe group of women allegedly robbed two Catbird stores and one Gorjana location on the afternoon of March 9.
FinancialsMar 23, 2026
Movado’s Q4 Sales Rise As Demand Grows From Younger Shoppers, WomenMovado CEO Efraim Grinberg noted continued strength in the fashion watch and accessible luxury segments in the U.S.
TrendsMar 23, 2026
Marco Bicego’s New Campaign Showcases ‘The Art of Craft’After celebrating 25 years in 2025, the campaign marks a new chapter for the jewelry brand with the message that “Identity Creates Value.”
Events & AwardsMar 23, 2026
These Watch Brands Are Heading to Couture This YearCouture and Time to Watches announced the watch brands, from big names to independents, attendees will see at the show.
FinancialsMar 20, 2026
Macy’s Turnaround Plans Shows Promise, Boosted by Bloomingdale’sPlus, why Saks Global’s bankruptcy may have given Bloomingdale’s an edge.
AuctionsMar 20, 2026
Sotheby's, De Beers Unveil ‘Jwaneng 28.88’ DiamondThe flawless, Type IIa stone is estimated to achieve up to $2.8 million at the auction house’s high jewelry sale in April.
TrendsMar 20, 2026
‘Frankenstein’ Costume Designer Is Bejeweled In Brooches for Oscars WinCostume designer Kate Hawley wore three archival Tiffany & Co. brooches, our Pieces of the Week, while accepting her first Oscar.
FinancialsMar 19, 2026
Signet Jewelers to Close 100 Stores, Shutter James Allen BannerThe jewelry retailer announced changes to its store network and brand portfolio during its fourth-quarter earnings call.
SurveysMar 19, 2026
NRF Forecasts 4% Retail Sales Growth in 2026From a weaker labor market to inflation, NRF Chief Economist Mark Mathews gave insight on what retailers can expect this year.
AuctionsMar 19, 2026
26-Carat Diamond Tops $1M at AuctionThe historic stone, which sold at Elmwood’s in London, is the largest white diamond to be offered on the U.K. market in more than a decade.
Events & AwardsMar 19, 2026
JCK Rocks To Ride With NellyThree-time Grammy award-winning artist Nelly is set to perform at the annual event at Tao Beach in Las Vegas on May 31.
AuctionsMar 18, 2026
Collection of the ‘Severely Beautiful’ Lady Wardington Fetches $161KThe model and fashion editor’s gold evening bags were the top lots at the London sale, going for more than $25,000 each.
