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
Policies & IssuesJul 07, 2025
Higher Tariffs Set to Take Effect Aug. 1, Officials SayThe announcement comes just as the 90-day freeze on the “reciprocal” tariffs nears its end, giving countries more time to negotiate.
MajorsJul 07, 2025
Natural Diamond Council CEO David Kellie To Step DownKellie, who joined the organization in 2019, will remain in his role through the end of 2025.
CrimeJul 07, 2025
7 Suspects Charged in California Jewelry Store BurglaryPolice officers apprehended the suspects as they were allegedly attempting to gain entry into another jewelry store.
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.
Events & AwardsJul 07, 2025
Applications Open for Ella Klein Internship The program, a collaboration between Julius Klein Diamonds and the Women’s Jewelry Association, is in its second year.
Weekly QuizJul 02, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
Supplier BulletinJul 03, 2025
Protect Your Customers and Your BusinessSponsored by the Gemological Institute of America
MajorsJul 03, 2025
Brilliant Earth Names Tennis Star Madison Keys as Its New AmbassadorThe 2025 Australian Open champion is the jewelry brand’s first athlete ambassador.
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.
MajorsJul 03, 2025
Muse Sets Up Shop in Nordstrom’s New Jewelry HallThe West Village jewelry boutique’s new shop-in-shop is the cornerstone of Nordstrom’s revamped jewelry hall.
SourcingJul 03, 2025
SRK Announces Its Natural Diamonds Are Now Carbon-NegativeThis past year, the manufacturer said it recorded below-zero emissions per carat of natural diamond.
CollectionsJul 03, 2025
Piece of the Week: A Firework of Diamonds From YepremThe brand’s “Golden Strada” statement necklace features round, marquise, and pear diamonds that sparkle like Fourth of July fireworks.
CrimeJul 03, 2025
JSA Shares Holiday Weekend Security Tips Amid Spike in BurglariesJSA’s Scott Guginsky provided a list of nine security measures jewelers should observe while locking up for the long weekend.
MajorsJul 02, 2025
Boucheron Looks to LA for First West Coast FlagshipLocated on Rodeo Drive, the store’s design was inspired by Hollywood and Los Angeles culture.
MajorsJul 02, 2025
Marco Bicego Opens Milan FlagshipThe new location continues the brand’s celebration of its 25th anniversary.
WatchesJul 02, 2025
Chrono24 Revamps Brand, Launches New CampaignThe online watch marketplace’s “Time Is Our Thing” campaign highlights the importance of time.
SourcingJul 02, 2025
Bernadette Mack Joins Gem Legacy as Executive DirectorShe will oversee strategic planning, fundraising, industry partnerships, and the launch of the Gem Legacy Campus in Tanzania.
CrimeJul 02, 2025
Pandora, Amazon Partner to Uncover Counterfeit Jewelry NetworkWorking with Amazon’s Counterfeit Crimes Unit and law enforcement, Pandora helped to shut down a large-scale counterfeit network in China.
MajorsJul 01, 2025
Cast Closes Business, Plans for RelaunchThe jewelry company has closed its three California brick-and-mortar stores, as well as its online shop, for now.
Events & AwardsJul 01, 2025
William Goldberg Diamonds, FIT Partner for Apprenticeship ProgramThe company is providing the opportunity for an FIT student to work alongside master diamond cutter Willie Lopez in its workshop.
IndependentsJul 01, 2025
Elie Hannoush, Founder of Hannoush Jewelers, Dies at 73He is remembered for his successful entrepreneurship, generosity, and dedication to his family.
MajorsJul 01, 2025
Claire’s Is Looking for a Buyer, Report SaysThe jewelry store chain has reportedly been struggling with costs related to tariffs as well as tough retail competition.
TrendsJul 01, 2025
Amanda’s Style File: Red Hot RubiesWelcome warm summer days with red hot rubies perfectly chosen as July’s birthstone.
CollectionsJun 30, 2025
State Property’s New Jewelry Tells ‘The Story of Everything’Co-founders Afzal Imram and Lin Ruiyin brought their son’s story of a cosmic egg, toadstool, and railroad to life in their new collection.
ColumnistsJun 30, 2025
The Smart Lab: Why Q3 Is the Secret Weapon For Holiday Jewelry SalesThe best time to prepare for the holiday season is right now, according to columnist Emmanuel Raheb.
Events & AwardsJun 30, 2025
AGA Names Recipient of 2025 Gemological Education ScholarshipThis year’s winner is Morgan Keefe, who is currently studying at GIA to be a gemologist.
IndependentsJun 30, 2025
Melanie Grant’s New Book Explores 200 Years of Jewelry“The Jewelry Book” comes out this September.
TechnologyJun 27, 2025
Gemist Raises $6M in Funding to Scale Jewelry Tech PlatformThe company is focused on modernizing the custom jewelry buying experience with e-commerce tools like product visualization and 3D styling.
