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.”
Editors' Picks
Sponsored by
More on Lab-Grown
The Latest
MajorsMar 13, 2025
Tanishq Opens 2 New Stores in the U.S.The Indian jewelry brand recently opened stores in Atlanta and Seattle.
FinancialsMar 13, 2025
Brilliant Earth’s 2024 Sales Struggled Amid Engagement RecoveryCEO Beth Gerstein shared its most popular price points, what’s trending in non-bridal fine jewelry, and its holiday performance.
CollectionsMar 13, 2025
Chopard Unveils High Jewelry Collection Created From 6,225-Carat Emerald The 15 pieces were crafted from the “Insofu” emerald, discovered in Zambia in 2010.
Brought to you by
Watch: GIA Field Gemology at the One-Hundredth Expedition: A Look Back and to the FutureSupplier Spotlight Sponsored by GIA
MajorsMar 13, 2025
Jewelers Mutual Names New CFO, TreasurerChris Anderson is joining the insurance provider as the new chief financial officer and treasurer.
Weekly QuizMar 06, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
SourcingMar 12, 2025
5 Factors That Will Impact the Diamond Industry in 2025The industry is changing as it grapples with new realities around distribution, supply, and the need for consistent, effective marketing.
SourcingMar 12, 2025
Q&A: New GJEPC Chairman Kirit BhansaliBhansali discusses the potential impact of U.S. tariffs, demand for diamonds by market, and the “cautious confidence” in India right now.
Brought to you by
Natural Diamonds Should Mean MoreNatural diamonds mean more than lab-grown, but when every cut is ideal, they all look the same. Customers want more—Facets of Fire delivers.
SourcingMar 12, 2025
Indian Leader, Retailer Among 2025 DDG Honorees Govind Dholakia and Tanishq will be recognized for their contributions to the industry at the Diamonds Do Good Awards in Las Vegas.
IndependentsMar 12, 2025
Marla Aaron Migrates to LondonThe New York City-based brand has opened its first U.K. location with a permanent shop-in-shop at Liberty in London.
AuctionsMar 12, 2025
A Medieval Bishop’s Sapphire Ring Is Going Up for SaleA metal detectorist discovered the ring that is believed to have belonged to a bishop in the late 12th to early 13th century.
Events & AwardsMar 12, 2025
JA New York Announces Education, Live Demo LineupsOrganizers looked to new partnerships and interactive experiences to enhance the spring show, set for March 16 to 18.
Events & AwardsMar 12, 2025
Bogolo Joy Kenewendo to Speak at Annual JVC LuncheonKenewendo, Botswana’s minister of minerals and energy, will discuss the future of diamonds.
CrimeMar 11, 2025
Man in Florida Swallows Allegedly Stolen Tiffany & Co. Jewelry The suspect allegedly stole almost $800,000 worth of diamond jewelry from a store in Orlando and then swallowed it during a traffic stop.
ColumnistsMar 11, 2025
Creative Connecting: How to Pose on the Red CarpetAhead of the Gem Awards on Friday, Jen Cullen Williams and Duvall O’Steen share pro tips for taking the best photos.
CollectionsMar 11, 2025
Marco Bicego Celebrates 25 Years With Collection, CampaignFounded in 2000, Marco Bicego is commemorating its milestone anniversary with a “25 Best” collection and campaigns honoring its heritage.
TechnologyMar 11, 2025
Hill & Co. Launches New B2B Buyer DatabaseThose attending the company’s upcoming Zoom workshop will receive early access to “The List,” its new resource for finding buyers.
Events & AwardsMar 11, 2025
JSA to Honor GIA Employee at Annual LuncheonThe organization will present an award to Amy-Elise Signeavsky, law enforcement and diamond recovery manager at GIA.
MajorsMar 10, 2025
Terry Chandler to Retire After 24 Years as Head of DCA Chandler started his jewelry career at Michelson Jewelers, joining the Diamond Council of America as president and CEO in 2001.
CollectionsMar 10, 2025
MaeVona Co-Founder Debuts 3D-Printed ‘Tùsaire’ CollectionScottish American designer Maeve Gillies collaborated with Platinum Guild International on jewelry created by direct metal 3D printing.
Events & AwardsMar 10, 2025
The Jewelry Symposium Announces 2025 Scholarship WinnersAhead of its trade show in May, TJS awarded free registration and accommodations to five up-and-coming jewelry industry professionals.
Events & AwardsMar 10, 2025
These Designers, Journalists, and Retailers Are Up for a Gem Award The 2025 Gem Awards are set to take place Friday at Cipriani 42nd Street in New York City.
MajorsMar 07, 2025
Jane Fonda, Mariska Hargitay Star in Pomellato’s IWD CampaignThe annual star-studded campaign for International Women’s Day encourages collective action against domestic violence.
CollectionsMar 07, 2025
Piece of the Week: Yeprem’s ‘Golden Strada’ NecklaceThe statement piece is seen in Yeprem’s new “You Play the Game” campaign, created for International Women’s Day.
MajorsMar 07, 2025
Borsheims Names New Senior Security and Facilities ManagerLongtime employee Kyle Slosson has been promoted to the role.
IndependentsMar 06, 2025
Wixon Jewelers to Close After 37 YearsFirst-generation jewelers Dan and Hope Wixon are retiring and will close their Minneapolis-area jewelry store in May.
CollectionsMar 06, 2025
Guzema, 3.1 Phillip Lim Collab on New ‘Snake’ DesignsThe limited-edition collection, a nod to the Year of the Snake, is Ukrainian brand Guzema’s first partnership with a U.S. brand.
