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
TrendsJun 20, 2025
Dua Lipa Stays On-Trend With Chunky Engagement RingThe singer’s ring ticks off many bridal trends, with a thick band, half-bezel setting, and solitaire diamond.
TrendsJun 20, 2025
Piece of the Week: Yvonne Léon’s ‘Python Gold’ BraceletThe bracelet references vintage high jewelry and snake symbolism as a playful piece where a python’s head becomes a working belt buckle.
CrimeJun 18, 2025
7 Men Indicted in $100M Brinks Jewelry HeistThe heist happened in Lebec, California, in 2022 when a Brinks truck was transporting goods from one show in California to another.
Brought to you by
Investing in the Next Generation of Bench JewelersThe Seymour & Evelyn Holtzman Bench Scholarship from Jewelers of America returns for a second year.
AuctionsJun 18, 2025
Historic ‘Marie-Thérèse Pink’ Diamond Fetches $14M at Christie’sThe 10-carat fancy purple-pink diamond with potential links to Marie Antoinette headlined the white-glove jewelry auction this week.
Weekly QuizJun 20, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
EditorsJun 18, 2025
Q&A: Caryl Capeci Dives Into Cruise Jewelry ShoppingThe Starboard Cruises SVP discusses who is shopping for jewelry on ships, how much they’re spending, and why brands should get on board.
AuctionsJun 18, 2025
16th-Century ‘Gresham Grasshopper’ Ring Sells for $56KThe historic signet ring exceeded its estimate at Noonans Mayfair’s jewelry auction this week.
Brought to you by
Jewelers of America is Headed to Las Vegas for JCK 2025The countdown is on for the JCK Las Vegas Show and JA is pulling out all the stops.
CollectionsJun 18, 2025
Kirk Kara Celebrates 135 Years With New JewelsTo mark the milestone, the brand is introducing new non-bridal fine jewelry designs for the first time in two decades.
SourcingJun 18, 2025
Gemfields Sells 36-Carat Rough RubyThe gemstone is the third most valuable ruby to come out of the Montepuez mine, Gemfields said.
TechnologyJun 18, 2025
Alex Brown Named President of Smithee GroupFounder and longtime CEO Ben Smithee will stay with the agency, transitioning into the role of founding partner and strategic advisor.
EditorsJun 17, 2025
The Best New Jewelry from Couture 2025, Part 1Associate Editor Natalie Francisco shares 20 of her favorite pieces from the jewelry collections that debuted at Couture.
ColumnistsJun 17, 2025
Peter Smith: Is Your Comp Plan a Hiring Hindrance?If you want to attract good salespeople and generate a stream of “sleeping money” for your jewelry store, then you are going to have to pay.
AuctionsJun 17, 2025
Colored Gemstones, Signed Jewels Shine in Sotheby’s High Jewelry SaleThe top lot was a colorless Graff diamond, followed by a Burmese ruby necklace by Marcus & Co.
MajorsJun 17, 2025
Amanda Gizzi Gets a Promotion at JAGizzi, who has been in the industry since 2001, is now Jewelers of America’s senior vice president of corporate affairs.
MajorsJun 17, 2025
Kering Names Automotive Exec as Its New CEOLuca de Meo, a 30-year veteran of the auto industry, will succeed longtime CEO François-Henri Pinault.
EditorsJun 16, 2025
Q&A: Bogolo Joy Kenewendo on Mining, Tariffs, and the Energy of Las VegasFollowing visits to Vegas and New York, Botswana’s minerals minister sat down with Michelle Graff to discuss the state of the diamond market.
IndependentsJun 16, 2025
Greenwich St. Jewelers Launches Commitment Campaign Celebrating LGBTQ+ CouplesThe “Your Love Has the Perfect Ring” campaign showcases the strength of love and need for inclusivity and representation, the jeweler said.
MajorsJun 16, 2025
Ivette Nersesyan-Stephanopoulos Joins Tiffany & Co.The former De Beers executive is the jewelry house’s new director of high jewelry for the Americas.
MajorsJun 16, 2025
Catbird Names WNBA Star Nyara Sabally as Its New Brand AmbassadorThe New York Liberty forward is the first athlete to represent the Brooklyn-based jewelry brand.
CollectionsJun 13, 2025
Piece of the Week: Robinson Pelham’s Pear EarringsTake a bite out of the 14-karat yellow gold “Fruits of Love Pear” earrings featuring peridots, diamond stems, and tsavorite leaves.
Events & AwardsJun 13, 2025
AGA to Host ‘Diamonds From Mine to Market’ Education ConferenceThe one-day virtual event will feature speakers from De Beers, GIA, and Gemworld International.
EditorsJun 12, 2025
15 Questions With Jewelry Photographer Ella SophieThe California-based creative talks jewelry photography in the modern era and tackles FAQs about working with a pro for the first time.
AuctionsJun 12, 2025
Vintage Patek Philippe From the ‘50s Sells for $4M at Sotheby’s Al Capone’s pocket watch also found a buyer, though it went for less than half of what it did at auction four years ago.
Events & AwardsJun 12, 2025
Gabriel Love Foundation Introduces Scholarship Honoring Elias GabrielThe foundation has also expanded its “Stronger Together” initiative with Jewelers for Children.
AuctionsJun 12, 2025
Former De Beers Exec Celine Assimon Joins BonhamsAssimon is the auction house’s new chief commercial officer.
EditorsJun 11, 2025
Q&A: Al Cook on Differentiating Natural Diamonds, Traceability, and TariffsThe De Beers Group CEO discusses the company’s new “beacon” program, the likelihood diamonds will be exempt from tariffs, and “Origin.”
