TechnologyMay 01, 2026
Gemist, Saban Onyx Partner on Retailer-Focused Customization OfferingTheir partnership combines Gemist’s customization technology with Saban Onyx’s U.S.-based manufacturing capabilities.
GradingOct 19, 2016
GIA Examines 5- and 10-Carat Lab-Grown Diamonds
The laboratory said the 5.19-carat diamond represents a “significant milestone” in CVD diamond growing.
Examined by the GIA’s Hong Kong laboratory, this 5.19-carat CVD synthetic diamond is J-equivalent color and VS2-equivalent clarity. It is one of two lab-grown diamonds discussed in research articles published recently by the lab. (Photo credit: Johnny Leung and Tony Leung, courtesy of GIA)
Carlsbad, Calif.--The Gemological Institute of America recently examined two large lab-grown diamonds submitted to its Hong Kong lab, one of which represents a “significant milestone” in diamond growing.
In a research article authored by Billie “Pui Lai” Law and Wuyi Wang, the GIA said it recently examined a 5.19-carat diamond grown using the chemical vapor deposition process.
The stone, which is J-equivalent color and VS2-equivalent clarity, is the largest CVD-grown diamond examined by the lab to date, and the largest ever reported in the jewelry industry.
Breaking the 5-carat barrier is a “significant milestone” for CVD technology, which has been producing bigger diamonds in recent years, a trend that’s expected to continue.
As the GIA noted, “As diamond growth techniques continue to advance, we expect to see more high-quality samples, both in size and clarity.”
The article also stated that the 5.19-carat diamond was submitted to the lab without proper disclosure.
However, the GIA was able to identify it as a CVD synthetic using its standard screening and testing processes, though the lab noted that black inclusions, which often are contained in synthetic diamonds, were not found in this CVD diamond, meaning it could have been mistaken as a mined diamond if only microscopic examination was used.
The identification of this lab-grown diamond “highlights the importance of using advanced spectroscopic instruments as well as conventional gemological techniques to ensure an accurate identification,” the GIA said.
The second article, authored by Wang and Terry “Ping Yu” Poon, discussed the examination of a 10.08-carat blue diamond grown by St. Petersburg, Russia-based New Diamond Technology. NDT is the same company that grew the 5.03-carat blue diamond examined by the GIA’s New York laboratory earlier this year.
Grown using the high-pressure, high-temperature method and disclosed as a synthetic diamond by NDT, the stone is the largest HPHT-grown diamond recorded to date.
The GIA said the emerald-cut stone has a color grade equivalent to fancy deep blue.
Editors' Picks
Sponsored by
More on Grading
The Latest
SurveysMay 01, 2026
Consumer Confidence Inches Up in April Despite Rising Gas PricesRespondents were concerned about the Middle East conflict and how it will impact their finances.
CollectionsMay 01, 2026
A ‘Hidden Garden’ Emerges in Tiffany & Co.’s 2026 Blue BookOur Piece of the Week, the “Butterfly” necklace, showcases a 7.02-carat oval diamond set between diamond, platinum, and 18-karat gold wings.
Brought to you by
Discover Timeless Treasures: A Showcase of Antique Jewelry & Timepieces in Las VegasGain access to the most exclusive and coveted antique pieces from trusted dealers during Las Vegas Jewelry Week.
ColumnistsApr 30, 2026
Peter Smith: A Sleazy Salesman and the Case for Regret Avoidance Smith uses a comment he overheard in the grocery store to remind retailers that their job is to inspire buying behavior, not just sell.
Weekly QuizApr 30, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsApr 30, 2026
Claire’s New Summer Campaign Is a Sensory Wonderland for Gen Alpha“A Girl SMR at Claire’s” celebrates girlhood through the five senses with stacked jewelry, slime toys, scented accessories, and ASMR.
AuctionsApr 30, 2026
Vintage Cartier Watch Crashes Through Records, Selling for $2MBelieved to be one of three made in 1987, the Cartier London Crash was hot at the “Shapes of Cartier” sale at Sotheby’s Hong Kong.
Brought to you by
Las Vegas Antique Jewelry & Watch Show: Showcasing the Most Collectible Merchandise from Across the GlobeGain access to the most exclusive and coveted antique pieces from trusted dealers during Las Vegas Jewelry Week.
CrimeApr 30, 2026
Masked Group Uses Hammers, Pepper Spray in Texas Jewelry Store RobberyOfficials are looking for a group that robbed Marc Robinson Jewelers at an outlet mall in Round Rock, Texas, in broad daylight on April 21.
Supplier BulletinApr 30, 2026
OROAREZZO 2026: The B2B Event for Italian Excellence in Goldsmith, Jewelry and Silver ManufacturingSponsored by OROAREZZO International Jewelry Exhibition
TechnologyApr 29, 2026
The Thought Process Behind the Mother's Day Email Opt-OutSome retailers are taking a nuanced approach to marketing what can be a difficult holiday for many.
IndependentsApr 29, 2026
Dick Abbott to Retire From The EdgeThe Edge has announced its new CEO, as well as a new partnership with an investment firm focused on founder-led software businesses.
SourcingApr 29, 2026
De Beers’ Production Rises, Market Remains ‘Challenged’De Beers’ diamond production was up 17 percent in Q1, boosted by increased output at its mines in South Africa and Canada.
AuctionsApr 29, 2026
This'll Be the Day You Own John Wayne's RingA signet ring belonging to the Western film star of Hollywood’s Golden Age will be up for auction at Elmwood’s next month.
Policies & IssuesApr 28, 2026
Tariff Refunds: How to File, What to Expect Importers can submit claims now to receive money back for the IEEPA tariffs they’ve paid, with refunds expected to take up to 90 days.
IndependentsApr 28, 2026
This North Carolina Jeweler Is Passing the TorchThe owners of Gregory Jewelers in Morganton, North Carolina, are heading into retirement.
SourcingApr 28, 2026
Doug Hucker Retires From ICAThe colored gemstone industry leader is heading into retirement after four years as the association’s CEO.
SourcingApr 28, 2026
NDC Hires Tapestry Exec to Head Global Marketing Susie Dewey joins the Natural Diamond Council as its new chief marketing officer.
AuctionsApr 27, 2026
12 Years Later, the ‘Ocean Dream’ Diamond Resurfaces at Christie’sThe largest known fancy vivid blue-green diamond could fetch more than $12 million at its second auction appearance.
ColumnistsApr 27, 2026
Stop Treating Mother’s Day Like an AfterthoughtEmmanuel Raheb says jewelers need to start marketing early and make it easy for customers to pick a gift for mom.
IndependentsApr 27, 2026
Longnecker Jewelry Celebrates 30 YearsIn honor of the milestone, the Nebraska jeweler has debuted Leslie & Co., its new in-house jewelry brand.
MajorsApr 27, 2026
JBT Re-Elects Jeff Corey as Board ChairThe trade organization, which held its annual elections earlier this year, also added five new board members.
SurveysApr 24, 2026
Mother’s Day 2026 Jewelry Spending to Top $7B, NRF SaysNRF’s annual survey found that 45 percent of consumers plan to purchase jewelry for a loved one this Mother’s Day.
TechnologyApr 24, 2026
TwentyFour’s Digital-Age Locket Is a Virtual VaultThe “Vault” charm, our Piece of the Week, expands on the memories that can be stored in a locket by connecting to your phone.
Events & AwardsApr 24, 2026
Hamptons Jewelry Show to Return in JulyThe open-to-the-public luxury jewelry and timepiece show, in its second year, is slated for July 23-26.
IndependentsApr 23, 2026
Meet the Real Moms of Day’s JewelersThe jeweler’s Mother’s Day campaign highlights the women who work there—mothers, grandmothers, women who want to be mothers, and dog moms.
Supplier BulletinApr 23, 2026
JM® Shipping Solution: Smarter Shipping for High-Value GoodsSponsored by Jewelers Mutual
