Grading

GIA Spots Second Natural Diamond with Lab-Grown Layer

GradingMay 22, 2019

GIA Spots Second Natural Diamond with Lab-Grown Layer

The stone is 0.64 carats and graded as a fancy grayish-greenish blue.

20190522_lab_grown_natural_header.jpg
Gemological Institute of America researchers said the gray and blue components from the lab-grown layer of this diamond combined with the yellow from the natural substrate to create the color, fancy grayish-greenish blue. (Photo credit: Robison McMurtry)

Carlsbad, Calif.—GIA researchers recently spotted a second natural diamond with a lab-grown layer that added weight and improved the color, and warned that it could mean the trade will see more of these kind of composites.

According to an article by Troy Ardon and Garrett McElhenny in the spring 2019 edition of “Gems & Gemology,” the presence of both boron- and nitrogen-related defects—which are rarely seen together in natural diamonds—tipped them off there was something unusual about the stone.

The DiamondView fluorescence image of the diamond—a 0.64-carat fancy grayish-greenish blue cushion modified brilliant—showed a blue hue caused by the “cape” peak (nitrogen defect) and natural growth features.

The crown image, however, revealed a greenish-blue color common to boron-bearing diamonds and the dislocation patterns typically seen in diamonds grown using the chemical-vapor deposition (CVD) process.

In addition, a side view shows a distinct layer between the natural substrate and the CVD-grown portion of the stone.

This image shows the line of demarcation between the natural diamond and the CVD-grown layer. (Photo credit: Garrett McElhenny)

“These two distinct fluorescence patterns—the greenish-blue from the CVD layer and the darker blue from the naturally grown layer—prove that a layer of CVD synthetic diamond was grown on a natural substrate,” the article states.

A similar diamond, a 0.33-carat fancy blue that was also Type IIb with a CVD layer, was submitted to GIA in May 2017.

The CVD layer on this latest diamond is substantially thicker, 200 microns (approximately the thickness of two strands of human hairs) vs. 80 microns on the 0.33-carat diamond evaluated two years ago, and GIA noted that seeing a second example of this same type of composite could signal a new type of product entering the market.

The lab would not say if both diamonds came from the same client.

GIA also declined to comment on how the stones were submitted—as natural diamonds, or as natural/lab-grown composites—but did note that clients submitting goods are required to disclose all known treatments as well as whether a stone is natural or man-made.

To see more from the spring 2019 edition of “Gems & Gemology,” the Gemological Institute of America’s quarterly research journal, visit GIA.edu.

Michelle Graffis the editor-in-chief at National Jeweler, directing the publication’s coverage both online and in print.

The Latest

Fabergé x 007 Octopussy egg and pendant
CrimeDec 04, 2025
Man Arrested After Allegedly Swallowing Fabergé Egg Pendant

The man was charged with theft, accused of ingesting the necklace while in a jewelry store in Auckland, New Zealand.

Exterior of renovated and expanded J.R. Dunn Jewelers
IndependentsDec 04, 2025
Step Inside JR Dunn Jewelers’ Giant New Store

The Florida independent expanded its store from 8,000 to 14,000 square feet, fulfilling the vision of its late co-founder, Jim Dunn.

DD-Email-Image-1872x1052 (1).jpg
Supplier BulletinDec 04, 2025
Introducing Shop Natural Day: A New Movement Celebrating Natural Diamonds

Sponsored by De Beers Group

Recipients Collage 2025 - NJ (1872 x 1050 px) (1872 x 1052 px).png
Brought to you by
Impacting Tomorrow Today

How Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.

G-Shock DWN5600 Ring
WatchesDec 04, 2025
Casio Shrinks its G-Shock Watch

The classic 5600 series G-Shock has been scaled down to about a tenth of its size, becoming a fully functioning watch ring.

Weekly QuizDec 04, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Accredited Gemologists Association logo
Events & AwardsDec 04, 2025
AGA Announces 2026 Tucson Speaker Lineup

The association’s annual conference and gala will take place Feb. 4, 2026, during the Tucson gem shows.

 CBG logo
Events & AwardsDec 04, 2025
CBG Announces Speaker Lineup for 2026 Miami Event

The January show will include a workshop for jewelry retailers on implementing AI to strengthen their businesses.

roseco-catalog.png
Brought to you by
Roseco Releases New Full-Line Catalog

Roseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.

Miley Cyrus and Maxx Morando Engagement Ring
TrendsDec 03, 2025
Miley Cyrus Debuts Edgy Engagement Ring

Fellow musician Maxx Morando proposed to the star with a chunky, cushion-cut diamond ring designed by Jacquie Aiche.

Costco store
Policies & IssuesDec 03, 2025
Costco Joins Growing Wave of Retailers Suing for Tariff Refunds

The retailer, which sells billions in fine jewelry and watches, is suing the Trump administration and U.S. Customs and Border Patrol.

Shoppers in a mall
SurveysDec 03, 2025
A Record 202.9M Shoppers Turned Out Thanksgiving Weekend

Black Friday is still the most popular shopping day over the five-day holiday weekend, as per the National Retail Federation’s survey.

Faberge The Winter Egg
AuctionsDec 03, 2025
Fabergé’s 'The Winter Egg' Achieves Record $30M

The historic egg, crafted for Russia's ruling family prior to the revolution, was the star of Christie’s recent auction of works by Fabergé.

Vera Wang Love lab grown diamond engagement ring
FinancialsDec 02, 2025
Signet Jewelers’ Q3 Sales Up Amid Continued Focus on Lower Price Points

The retailer offered more fashion jewelry priced under $1,000, including lab-grown diamond and men’s jewelry.

Briony Raymond holding Briony Raymond Eau De Parfum
CollectionsDec 02, 2025
Briony Raymond Introduces First Fragrance

The eau de parfum is held in a fluted glass bottle that mirrors the decor of the brand’s atelier, and its cap is a nod to its “Sloan” ring.

The Finsch diamond mine in South Africa, owned by Petra Diamonds Ltd.
SourcingDec 02, 2025
Petra Diamonds Elevates Interim CEOs to Permanent Status

Vivek Gadodia and Juan Kemp, who’ve been serving as interim co-CEOs since February, will continue to lead the diamond mining company.

Lee Krombholz, Michael Coan, Donna DeLucia, Joanna Joy Seetoo
MajorsDec 02, 2025
Lee Krombholz Takes Over as Chair of MJSA Education Foundation

In addition, a slate of new officers and trustees were appointed to the board.

Retail Jewelers Organization logo
IndependentsDec 02, 2025
RJO Welcomes Its 1,200th Retail Member

Witt’s Jewelry in Wayne, Nebraska, is the organization’s new milestone member.

Gemologist, geologist, and editor Brendan M. Laurs
SourcingDec 02, 2025
Brendan Laurs Honored With 2025 Bonanno Award

Laurs is the editor-in-chief of Gem-A’s The Journal of Gemmology and an expert on the formation of colored gemstone deposits.

Empress Eugénie pearl and diamond tiara
CrimeDec 01, 2025
Fourth Man Charged in Louvre Jewelry Heist

The man, who has a criminal history, is suspected of being the fourth member of the four-man crew that carried out the heist.

Van Cleef & Arpels zipper necklace Christies
AuctionsDec 01, 2025
Christie’s Presents ‘Splendor & Style’ Collection

The single-owner collection includes one of the largest offerings of Verdura jewels ever to appear at auction, said Christie’s.

Lustig Jewelers employees in store
IndependentsDec 01, 2025
Lustig Jewelers’ New Owner Is a Fellow Chicago Jeweler

Michael Helfer has taken the reins, bringing together two historic Chicago jewelry names.

Retrouvaí Classic Diamond Domino Necklace and Kwiat Entwine Platinum and Diamond Drop Earrings
MajorsDec 01, 2025
PGI Debuts Platinum-Filled Holiday Gift Guide

The guide features all-new platinum designs for the holiday season by brands like Harwell Godfrey, Ritani, and Suna.

Movado Connect 2.0 watches
FinancialsNov 26, 2025
Movado CEO Talks Tariffs, Growing Interest in Accessible Luxury Watches

During its Q3 call, CEO Efraim Grinberg discussed the deal to lower tariffs on Swiss-made watches, watch market trends, and more.

Rosior Pumpkin Ring
TrendsNov 26, 2025
Piece of the Week: Rosior’s Pumpkin Ring

Rosior’s high jewelry cocktail ring with orange sapphires and green diamonds is the perfect Thanksgiving accessory.

Greenwich St. Jewelers Embrace Your True Colors Holiday Campaign
IndependentsNov 26, 2025
Greenwich St. Jewelers Launches Colorful Holiday Campaign

The “Embrace Your True Colors” campaign features jewels with a vibrant color palette and poetry by Grammy-nominated artist Aja Monet.

Alejandro Cuellar
MajorsNov 26, 2025
Serafino Consoli Names New VP of Sales, Brand Development for the Americas

Luxury veteran Alejandro Cuellar has stepped into the role at the Italian fine jewelry brand.

Grandview Klein scholarships
Events & AwardsNov 26, 2025
Grandview Klein Presents 4 Scholarships in Namibia

The company gave awards to four students at the Namibia University of Science & Technology, including one who is a Grandview Klein employee.

×

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