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
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.
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.
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.
Weekly QuizMar 19, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
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.
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.
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.
PodcastsMar 18, 2026
Episode 3: An Interview With Jewelry Designer Johnny NelsonFresh off winning the David Yurman Gem Awards Grant, Nelson discusses the ring that launched his career and his plans for the future.
SourcingMar 18, 2026
Lucara Recovers Nearly 37-Carat Blue DiamondThe “stunning” Type IIb stone was found via x-ray technology at its Karowe mine in Botswana.
MajorsMar 18, 2026
Stuller Releases New Edition of Jewelry Education Book“The Basics of Jewelry” has been updated to include modern topics and visuals.
Events & AwardsMar 17, 2026
The Best Moments From the 2026 Gem Awards Held just before the Oscars, the jewelry industry’s big awards show had its share of standout jewelry, gowns, and acceptance speeches.
SourcingMar 17, 2026
Cruzeiro Mine Debuts ‘Winter Tourmaline’The Brazilian mine’s new collection features cabochons in soft, muted shades like silver and lilac.
TrendsMar 17, 2026
Natalie Portman Is Tiffany & Co.’s New AmbassadorThe Academy Award-winning actress stars in Tiffany & Co.’s latest commercial, which debuted Sunday night during the Oscars.
MajorsMar 17, 2026
Kering Establishes Jewelry Division, Appoints CEOThe organizational change follows Kering’s promise of a transformation after declining sales in 2025.
EditorsMar 16, 2026
2026 Oscars Jewelry: One Necklace After AnotherNatalie Francisco rounds up the top Oscars jewels, including Rose Byrne’s Taffin necklace with a more than 20-carat yellow-brown diamond.
WatchesMar 16, 2026
TAG Heuer Has a New CEOBéatrice Goasglas has been with TAG Heuer since 2018. She is the first woman to head the 166-year-old, LVMH-owned watch brand.
IndependentsMar 16, 2026
Ben Bridge Debuts New Honolulu BoutiqueThe store features the first in-store build for the jeweler’s in-house “Bella Ponte” bridal brand.
AuctionsMar 16, 2026
Bonhams Paris To Offer Antique, Signed Jewels The live fine jewelry auction will take place later this week, showcasing antique pieces, rare gemstones, and signed jewels.
CollectionsMar 13, 2026
A Trio of Jewels from the 3 Gem Award Nominees for Jewelry DesignOur Pieces of the Week honor the 2026 nominees for the Gem Award for Jewelry Design, Silvia Furmanovich, Cece Fein-Hughes, and Catherine Sarr.
WatchesMar 13, 2026
Citizen, Vera Wang to Launch Watch CollectionThe 24-piece watch collection is set to debut in spring 2027.
SourcingMar 13, 2026
Andrea Pooler Joins Third-Generation Diamond Company as COO Pooler, who has more than 25 years’ experience in jewelry, is now chief operating officer of Modani Jewels, Soham Diamonds, and SNJ Creations.
MajorsMar 13, 2026
24 Karat Club of New York’s Banquet to Return to Waldorf AstoriaThe reopening of the Waldorf Astoria means a homecoming for the industry group’s annual event, which will take place Saturday.
CollectionsMar 12, 2026
Jessica McCormack Sends Gold, Gemstones Into ‘Orbit’McCormack looked to the 19th century’s “golden age” of astronomy when designing her new celestial-themed collection.
Events & AwardsMar 12, 2026
Johnny Nelson Wins David Yurman Gem Awards GrantNelson will be honored as the inaugural grant winner at the Gem Awards gala on Friday.
