ColumnistsMay 18, 2026
Edahn Golan: What a K-Shaped Economy Means for Fine JewelryIn a column for the 2026 State of the Majors issue, Golan spells out how the growing economic divide in the U.S. is reshaping the market.
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.
Editors' Picks
Sponsored by
More on Grading
The Latest
CollectionsMay 18, 2026
Foundrae’s New Collection Taps Into JoyThe “Limitless Expansion of Joy and Hope” collection evokes summer through colored gemstones and motifs of butterflies and florals.
CollectionsMay 18, 2026
Hancocks London Acquires Historic ‘Inchiquin’ EmeraldThe jewel, circa 1890, is from the late Victorian era and was owned by descendants of the last high king of Ireland.
Brought to you by
How Modern Training Is Becoming a Competitive Advantage for Jewelry RetailersWith the trade and customer trust in mind, GIA® developed NextGem™ – on-demand training designed specifically for retail.
Events & AwardsMay 18, 2026
Here Are the 2026 JCK Industry Fund Grant Recipients This is what the nine recipients plan to do with the funds.
Weekly QuizMay 14, 2026
This Week’s QuizTest your jewelry news knowledge by answering these questions.
AuctionsMay 15, 2026
American Collector Ponies Up Almost $17K for John Wayne’s RingThe Western star’s 14-karat gold signet ring sold for six times its low estimate following a bidding war at U.K. auction house Elmwood’s.
Events & AwardsMay 15, 2026
JA, MJSA To Sponsor Roundtable at TJSThe discussion, "Rebuilding the Jewelry Workforce," will take place on Saturday, May 16, in Troy, Michigan.
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.
SourcingMay 15, 2026
State of Diamonds: The Way Forward for Natural DiamondsThe jewelry industry is reassessing its positioning as Gen Z reshapes the retail landscape and lab grown continues to gain market share.
AuctionsMay 14, 2026
White Diamonds Lead Sotheby’s Auction, Blue Diamond Does Not SellA matching pair of 18.38-carat, D-color diamonds from Botswana’s Jwaneng mine sold for $3.3 million, the top lot of the jewelry auction.
Supplier BulletinMay 14, 2026
A Diamond Is Forever Continues Desert Diamonds – Bridal ReinvigoratedSponsored by A Diamond Is Forever
SourcingMay 14, 2026
State of Colored Stones: The Spirit of Young American Gemstone CuttersThe next generation of lapidarists are entrepreneurial, engaged online, and see the craft as a means for artistic expression.
AuctionsMay 14, 2026
‘Ocean Dream’ Makes Waves at Christie’s, Fetching $17MIt was the second auction appearance for the fancy vivid blue-green diamond, which sold for $7.8 million at Christie’s Geneva 12 years ago.
CrimeMay 14, 2026
Second Man Arrested in Florida Pawn Shop Shooting Members of the U.S. Marshals Task Force took a 22-year-old man into custody. He was charged with tampering with evidence.
CrimeMay 13, 2026
JSA’s 2025 Crime Report Shows ‘Concerning’ Rise in ViolenceWhile the overall number of crimes was down, there were more incidences in which robbers pulled out guns, mace, or rammed cars into stores.
IndependentsMay 13, 2026
New Orleans Jeweler Closing Canal Place StoreJack Sutton Fine Jewelry is closing its store inside the downtown shopping center after 40 years in business.
SourcingMay 13, 2026
Smithsonian Acquires ‘Winston Red’ Diamond PaintingReena Ahluwalia’s painting of the rare red diamond is the first contemporary painting to join the National Gem Collection.
TrendsMay 13, 2026
State of Design: Only the Innovative Will SurviveThe price of gold has risen, affecting the number of pieces designers make, the materials they use, and how they position themselves.
ColumnistsMay 12, 2026
It’s Official: We’re Getting ‘Brain Rot’ From Watching Short-Form Videos Peter Smith gives tips on leading meetings, developing marketing, and making trade show appointments in the age of short attention spans.
CollectionsMay 12, 2026
Jessica McCormack Debuts Antique Coin-Inspired Medallions for SummerThe 11-piece “Medallions” capsule collection features five motifs: a crying eye, a heart on fire, a spiral, a flower, and a swallow.
IndependentsMay 12, 2026
State of Retail: 6 Things Retailers Should Know About Consumers TodayFrom Gen Z’s view of luxury to “doom spending,” these are the six consumer trends to note this year.
Events & AwardsMay 12, 2026
The Tiffany & Co. x CFDA Jewelry Designer Award Is BackThe partners have announced the second cycle of the program, which has expanded to include a $25,000 student scholarship.
IndependentsMay 11, 2026
Kansas Jeweler Closing After 70 YearsThe owners of Staats Jewelers are heading into retirement.
TrendsMay 11, 2026
Former Macy’s CEO Joins Signet Jewelers BoardJeffrey Gennette, who retired in 2024 after 41 years with Macy’s, is the newest member of the jewelry retailer’s board of directors.
TrendsMay 11, 2026
Amanda’s Style File: Lucky May May babies are lucky to have emeralds, a gemstone admired for centuries, as their birthstone, writes Amanda Gizzi.
TechnologyMay 11, 2026
Clientbook’s New Tool Helps Jewelers Plan In-Store EventsThe new module allows retailers to plan, promote, and measure the success of events from a single dashboard.
Lab-GrownMay 08, 2026
NDC Publicly Criticizes Pandora Over ‘Misleading’ Natural Diamond ClaimsNDC said in an open letter that Pandora’s statements about the carbon footprint of lab grown versus natural diamonds are inaccurate.
