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
AuctionsOct 24, 2025
Bonhams Under New Ownership, Top Executives ReplacedLondon-based investment firm Pemberton Asset Management acquired the auction house for an undisclosed amount.
GradingOct 24, 2025
DMIA to Hold Diamond Testing Instrument DemoThe workshop will give attendees the chance to try out and ask questions about three different diamond verification instruments.
CrimeOct 24, 2025
Video Emerges of Louvre Jewelry Robbers Fleeing the Scene The footage shows two of the jewelry heist suspects descending from the second floor of the museum and then escaping via scooter.
Brought to you by
Are Earrings an Overlooked Category? What Retailers Need to Know NowAs the holiday season quickly approaches, consider stocking one category that sometimes gets overlooked: earrings.
CollectionsOct 24, 2025
Piece of the Week: Wyld Box Jewelry’s ‘Ray of Light’ EarringsFounder and designer Rosanna Fiedler looked to a vintage Cartier clutch when designing the sunlight-inspired drop earrings.
Weekly QuizOct 16, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
FinancialsOct 23, 2025
Jewelry Sales Resilient Despite Struggles at LVMH, KeringThe luxury conglomerates faced a challenging Q3 amid geopolitical and economic tensions.
SourcingOct 23, 2025
Petra Diamonds Turns to Shareholders to Raise Capital The struggling diamond mining company, which owns the historic Cullinan mine, has launched a rights issue to raise about $25 million.
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.
WatchesOct 23, 2025
‘Million Dollar Hip Hop Watches’ Recounts Watch HistoryThe book details the journey of watches as symbols of hard-earned success in hip-hop for artists like 2Pac, Jay-Z, and more.
AuctionsOct 23, 2025
Freeman’s | Hindman Names New VP, Senior Specialist for Jewelry & WatchesAlexis Vourvoulis, who most recently worked at Tiffany & Co., brings more than two decades of jewelry experience to her new role.
TrendsOct 22, 2025
The Taylor Swift Effect: Antique Diamonds EditionThe superstar’s August engagement put the stamp of approval on an already hot engagement ring trend.
TrendsOct 22, 2025
Don’t Forget These Diamond Jewelry Trends When Stocking for the HolidaysRetailers should offer classic styles with a twist that are a perfect fit for layered looks, experts say.
AuctionsOct 22, 2025
Pink Diamond, Vanderbilt Jewels to Headline Phillips’ Geneva AuctionThe nearly 7-carat fancy vivid purplish pink diamond could sell for around $9 million.
SourcingOct 22, 2025
In ‘Storied Diamond,’ Jared Jewelers Is Emphasizing the Journey The retailer’s new collection of engagement rings and fashion jewelry is set with natural diamonds that are traceable via blockchain.
CollectionsOct 22, 2025
Tiffany & Co.’s ‘Bird on a Rock’ Finds New PerchChief Artistic Officer Nathalie Verdeille has reimagined the iconic design in both figurative and abstract creations.
Events & AwardsOct 22, 2025
JFC Kicks Off Halloween Costume ChallengeFive dollars buys one vote toward an industry professional you want to see dressed up as a hero, or a villain, this Halloween.
Events & AwardsOct 22, 2025
Hillsborough Antique Show Gets New OwnerRecently acquired by KIL Promotions, the November edition of the public show in San Mateo, California, will be held Nov. 7-9.
GradingOct 21, 2025
GIA Examines Rare Bicolor Pink DiamondThe stone’s two zones, one pink and one colorless, may have formed at two different times, the lab said.
MajorsOct 21, 2025
Pomellato Brings ‘Global Attitude’ to Rodeo Drive FlagshipHollywood glamour meets Milanese sophistication in the design of Pomellato’s new store in Beverly Hills, California.
Events & AwardsOct 21, 2025
‘Douriean Fletcher: Jewelry of the Afrofuture’ Opens at MADThe Museum of Arts and Design's new exhibition features 75 pieces by the designer, best known for her work in the “Black Panther” films.
AuctionsOct 20, 2025
Sotheby's To Auction 10-Carat Vivid Pink DiamondMaking its auction debut, "The Glowing Rose" is expected to fetch $20 million at the November jewelry sale in Geneva.
SourcingOct 20, 2025
2 Mozambique Police Officers Killed at Gemfields’ Ruby MineThey were attacked on Oct. 15, as approximately 40 miners without licenses marched on the mine’s gate.
CrimeOct 20, 2025
See the ‘Priceless’ Jewels Stolen During Daytime Heist at the Louvre It took the masked thieves less than 10 minutes to steal eight irreplaceable jewels from two display cases in the museum’s Apollo Gallery.
SourcingOct 20, 2025
Pristine Gems Names New Director of European SalesGemologist Lauren Gayda has previously worked at The Clear Cut, Taylor & Hart, and Effy Jewelry.
IndependentsOct 17, 2025
From the Jazz Age to the Information Age: London Jewelers Turns 100In 2026, the jewelry retailer will celebrate a milestone only a small percentage of family-owned businesses survive to see.
Events & AwardsOct 17, 2025
An Edit of Italian Jewels Is Coming to NYCThe new showcase dedicated to Italian jewelry design is set for Oct. 29-30.
TrendsOct 17, 2025
Piece of the Week: Judi Powers Jewelry’s ‘Stella’ EarringsTake a gaze at the sky with this pair of platinum diamond-set star earrings with blue lace agate drops.
