MajorsDec 16, 2025
Pandora’s New CEO Will Step Up EarlyBerta de Pablos-Barbier will replace Alexander Lacik at the start of January, two months earlier than expected.
GradingApr 02, 2018
GIA Finds Synthetic Ruby Layer on Natural Gemstones
Though a lab-grown layer is nothing new, the absence of one element suggests different growth methods.
In this picture, a portion of the near-colorless corundum seed is revealed in an area where the synthetic ruby overgrowth was cut away. Photo credit: Hollie McBride/GIA
Carlsbad, Calif.--The Gemological Institute of America’s New York lab recently had a gemstone submitted for identification it hasn’t seen before.
According to an article by Tyler Smith and Hollie McBride in the winter 2017 issue of “Gems & Gemology,” the lab received two loose oval mixed-cut red gems for identification. Upon testing, the stones revealed refractive indices slightly higher than normal for corundum.
Higher refractive indices have been reported before for chromium-diffused corundum, in which extra chromium is added during heating to enhance the color. So, the article states, to the naked eye, the stones simply appeared to be chromium diffused and displayed red color concentrations at the intersections of the facets.
But further microscopic examination revealed a thin layer, about 0.3 mm thick, of “synthetic overgrowth”—a layer of lab-grown ruby that gave the stone its color—with a natural, almost-colorless sapphire at the core.
The authors said the two stones looked similar to Lechleitner synthetic overgrowth emeralds, named for Johann Lechleitner, who pioneered the process of giving a near-colorless beryl seed its green color with a synthetic emerald overgrowth in 1960. (The GIA’s lab in Carlsbad, coincidentally, received a Lechleitner emerald for identification around the same time the rubies were submitted.) 
Lechleitner also experimented with ruby overgrowth on both synthetic and natural corundum seeds.
While his specimens contained a number of elements, the two rubies submitted to the GIA were missing one—molybdenum—indicating there were different growth conditions present, according to the G&G article.
It noted that while this isn’t the first report of synthetic ruby overgrowth on natural sapphire seeds, it is the first time material featuring such aspects has been submitted to its New York and Carlsbad laboratories for identification.
“The resurfacing of these vintage overgrowth synthetics shows that once a material is in the trade, it is here to stay,” Smith and McBride said.
More on Grading
The Latest
AuctionsDec 16, 2025
Suzanne Belperron, JAR Shine in Sotheby’s First Auctions at New HQSotheby’s held its first two jewelry sales at the Breuer building last week, and they totaled nearly $44 million.
Events & AwardsDec 16, 2025
TJS Now Accepting Scholarship Applications for 2026Winners will receive free registration and lodging for its fourth annual event in Detroit.
Brought to you by
Impacting Tomorrow TodayHow Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.
ColumnistsDec 16, 2025
Beyond Unboxing: Creative Reveals to Drive Reach and EngagementHere are six ideas for making more engaging content for Instagram Reels and TikTok, courtesy of Duvall O’Steen and Jen Cullen Williams.
Weekly QuizDec 11, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
Events & AwardsDec 16, 2025
Diamonds Do Good Names 2026 Award RecipientsThe honorees include a notable jewelry brand, an industry veteran, and an independent retailer.
CrimeDec 15, 2025
Men Receive Life Sentences in Home Invasion Murder of Jeweler Carlos Jose Hernandez and Joshua Zuazo were sentenced to life without the possibility of parole in the 2024 murder of Hussein “Sam” Murray.
Brought to you by
Roseco Releases New Full-Line CatalogRoseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.
Policies & IssuesDec 15, 2025
Sara Yood Named Co-Chair of RJC Standards CommitteeYood will serve alongside Eduard Stefanescu, the sustainability manager for C.Hafner, a precious metals refiner in Germany.
IndependentsDec 15, 2025
M.S. Rau to Open Store in AspenThe New Orleans jeweler is also hosting pop-up jewelry boutiques in New York City and Dallas.
AuctionsDec 12, 2025
13.54-Carat Paraíba Tourmaline Sets Records at Christie’sSet in a Tiffany & Co. necklace, it sold for $4.2 million, the highest price and price per carat paid for a Paraíba tourmaline at auction.
MajorsDec 12, 2025
David Webb Reveals Ice-Cold Holiday Window DisplayThe jeweler’s “Deep Freeze” display showcases its iconic jewelry designs frozen in a vintage icebox.
CollectionsDec 12, 2025
Piece of the Week: Oscar Heyman’s Sphene RingTake luxury gifting to new heights this holiday season with the jeweler’s showstopping 12-carat sphene ring.
Events & AwardsDec 12, 2025
IGI Jewelry Design Contest Now Accepting SubmissionsThis year's theme is “Unveiling the Depths of the Ocean.”
TrendsDec 11, 2025
Pinterest 2026 Trend Report: Brooches, Bold Gold, Cool BlueIn its annual report, Pinterest noted an increase in searches for brooches, heirloom jewelry, and ‘80s luxury.
IndependentsDec 11, 2025
Look Inside Day’s Jewelers’ Ninth StoreThe 111-year-old retailer celebrated the opening of its new location in Salem, New Hampshire, which is its third store in the state.
MajorsDec 11, 2025
Americas Gold Releases New Gold Chain CatalogThe new catalog features its most popular chains as well as new styles.
AuctionsDec 10, 2025
Francis Ford Coppola’s Watch Sells for $10.8MThe filmmaker’s personal F.P. Journe “FFC” prototype was the star of Phillips’ recent record-setting watch auction in New York.
WatchesDec 10, 2025
There’s A New Rolex Boutique in MiamiThe new location in the Design District pays homage to Miami’s Art Deco heritage and its connection to the ocean.
SurveysDec 10, 2025
Consumer Confidence Drops in November Inflations, tariffs, and politics—including the government shutdown—were among consumers’ top concerns last month.
SourcingDec 10, 2025
NAJA Announces Details for 2026 ‘Ace It’ Winter Conference“Longtime favorite” presenters, as well as first-time speakers, will lead talks and workshops at the annual event in Tucson next year.
Events & AwardsDec 10, 2025
MJSA Names 2025 Responsible Design Challenge WinnerSilas Smith of Meridian Metalworks won the challenge with his pendant that blends Australian and American landscapes.
AuctionsDec 09, 2025
‘Desert Rose’ Diamond Sells for $8.8M in Abu DhabiThe sale of the 31.68-carat, sunset-hued stone was part of Sotheby’s first series of events and auctions in Abu Dhabi.
ColumnistsDec 09, 2025
Holiday Sales Happen in December, Most Decisions Don’tMost customers who walk into your store this month have made up their minds. Your job is to validate their choice, Emmanuel Raheb writes.
TrendsDec 09, 2025
‘Once Upon a Time,’ Guzema Debuted Its Holiday CollectionThe collection features characters and motifs from Ukrainian folklore, including an enchanted mirror and a magic egg.
TechnologyDec 09, 2025
Gemvision Releases Updated MatrixGoldMatrixGold 3.11, the newest version of the jewelry design program, offers more flexibility, precision, and creative control.
Events & AwardsDec 09, 2025
MJSA Showcase Pavilion Returning to JA New York The pavilion will be part of the 2026 JA New York Spring show, scheduled for March 15 to 17.
