GIA Examines Largest Known Diamond Grown Using CVD

Lab-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.

20220202_large CVD grown diamond.jpg
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 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 … 

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.

20220202_rough HPHT diamonds.jpg
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.”

The Latest

Alfred W. DeScenza
IndependentsApr 15, 2024
Alfred W. DeScenza of DeScenza Diamonds Dies at 95

He is remembered by loved ones for his loyalty, integrity, and kindness.

Joyce’s Jewelry
TechnologyApr 15, 2024
Judge Rules Jeweler’s Lawsuit Against PNC Bank Can Move Forward

Joyce’s Jewelry sued the bank after cybercriminals drained its accounts of nearly $1.6 million through a series of wire transfers.

Madeleine K. Albright
AuctionsApr 15, 2024
Madeleine K. Albright Jewelry, Pins Coming to Auction

Hosted by Freeman’s | Hindman, the sale will take place May 7-8.

Brought to you by
The Blueprint for Success in Scalable, Personalized Jewelry Retail

With Ho Brothers, you can unlock your brand's true potential and offer customers the personalized jewelry experiences they desire.

Audemars Piguet circa 1985 emerald car watch
AuctionsApr 15, 2024
All of Sotheby’s ‘Rough Diamonds’ Sold in Less Than an Hour

The auction house said all 24 timepieces offered in its underground sale of rare and avant-garde watches quickly found buyers.

Weekly QuizApr 11, 2024
This Week’s Quiz
Test your jewelry news knowledge with this seven-question quiz.
Take the Quiz
AGS Conclave 2024 logo Austin
Events & AwardsApr 15, 2024
10 Can’t-Miss Sessions at AGS Conclave 2024

From lab-grown diamonds and AI to the inevitable Taylor Swift mention, here are some of Conclave’s most intriguing educational offerings.

My Next Question webinar
Recorded WebinarsApr 12, 2024
Watch: What Jewelers Need to Know About Insurance

From cybersecurity liability to trade show coverage, insurance experts share tips on how to build the right policy.

Jewelers of America Fly In Washington, D.C.
Brought to you by
How Jewelers of America Represents Your Business

For over 30 years, JA has advocated for the industry, fought against harmful legislation and backed measures that help jewelry businesses.

Evil Eye Charm with Turquoise Disc
CollectionsApr 12, 2024
Piece of the Week: Lionheart’s Evil Eye Gemstone Charm

The charm is a modern rendition of the evil eye amulet that has been worn for thousands of years.

The Jewelry Symposium scholarship winners 2024
Events & AwardsApr 12, 2024
The Jewelry Symposium Announces 4 Scholarship Winners

Ahead of its trade show next month, TJS awarded free registration and accommodations to one jewelry professional and three students.

SRK Empire and SRK House
Policies & IssuesApr 11, 2024
SRK Exports’ Journey Toward Net Zero Impact

By the end of this year, SRK’s diamond manufacturing complexes will achieve net zero emissions, one of an impressive array of achievements.

Steven Rosdal
IndependentsApr 11, 2024
Steven Rosdal, Co-Founder of Hyde Park Jewelers, Dies at 77

He is remembered for his charisma, passion, integrity, kindness, and wit.

Macy’s Herald Square store
MajorsApr 11, 2024
Macy’s Opens Books for Possible Buyout

The retailer also appointed two new board members, avoiding a proxy fight from a potential buyer.

Sylvie Jewelry model
CollectionsApr 10, 2024
Sylvie Launches New Nature-Inspired Collection, ‘Tulira’

The bridal collection consists of 35 engagement rings and seven wedding bands.

Rolex Oyster Perpetual Deepsea in 18-karat yellow gold
WatchesApr 10, 2024
These Are Rolex’s New Watches for 2024

The crown introduced a dozen timepieces in Geneva, including a heavy metal version of its deep-sea divers’ watch.

Levy’s Fine Jewelry diamond education
IndependentsApr 10, 2024
Levy's Fine Jewelry Explores Diamond History

The family-owned jeweler has a new education section on its website dedicated to the history of diamond cutting.

With Clarity NFL wedding bands
CollectionsApr 10, 2024
With Clarity Partners With NFL on Wedding Bands

The limited-edition men’s rings can be customized with one of 12 team logos.

Asian Star’s diamond manufacturing facility in India
SourcingApr 10, 2024
Compliance, Caution, and Concern: The Current Outlook of Indian Diamantaires

There is a willingness to comply with new government-mandated regulations, with an insistence that they should be practical and realistic.

Chrono24 watch inspection lab
WatchesApr 09, 2024
Chrono24 Debuts Pre-Owned Watch Authentication Program

The program, now live in Europe, will roll out to the U.S. this summer.

6.21-carat fancy vivid pink diamond
AuctionsApr 09, 2024
Phillips to Offer 6.21-Carat Vivid Pink Diamond

Colored gemstones and signed jewels are the focus of its upcoming Geneva sale.

Lucapa rough colorless and pink diamonds
SourcingApr 09, 2024
Former De Beers Exec Appointed to Lucapa Board

Stuart Brown, who was De Beers’ CFO and interim CEO, is now Lucapa’s independent non-executive chairman.

Jewelers for Children POS System Donations
MajorsApr 09, 2024
Jewel360 Announces New POS Integration, JFC Partnership

The point-of-sale software can now prompt customers to round up their credit card purchases as a donation to Jewelers for Children.

Bharat Ratnam, a Mega Common Facilitation Centre (CFC)
SourcingApr 09, 2024
Reinvigorating SEEPZ, the Epicenter of India’s Studded Jewelry Exports

The zone’s modernization will enhance and increase India’s jewelry manufacturing capabilities while aiding small and mid-sized businesses.

Charles & Colvard moissanite bypass engagement ring
SourcingApr 08, 2024
Charles & Colvard Debuts B2B Portal for Moissanite

Select independent jewelers and retailers can now purchase moissanite through Charles & Colvard Direct.

Amber Rank
Events & AwardsApr 08, 2024
AGS Announces First Recipient of ‘Women in Leadership’ Scholarship

Amber Rank of Exclusively Diamonds will receive mentorship, registration to AGS’s 2024 Conclave, and $500.

Jaeger-LeCoultre citrine pinky-ring watch
AuctionsApr 08, 2024
Sotheby’s ‘Rough Diamonds’ Sale Is All About … Watches

The auction will take place Thursday and is underground, literally.

JOGS logo
Events & AwardsApr 08, 2024
JOGS Show Returns to Las Vegas for a Second Year

The trade show is moving downtown to the Expo at World Market Center.


This site uses cookies to give you the best online experience. By continuing to use & browse this site, we assume you agree to our Privacy Policy