EditorsSep 12, 2025
Out & About: Mining Sapphires in Rock Creek, MontanaAssociate Editor Lauren McLemore headed out West for a visit to Potentate Mining’s operation hosted by gemstone wholesaler Parlé Gems.
Lab-GrownJan 28, 2021
3 Moissanites With Fraudulent Inscriptions Submitted to GIA Lab
The stones were sent into the Johannesburg lab and researchers detailed their discovery in the fall issue of Gems & Gemology.
At left, the fraudulent inscription seen on the lab-grown moissanite, with the GIA report number partially redacted for privacy; at right, GIA’s standard procedure in cases of fraudulent inscriptions is to make the number illegible. (Photo by Tuan Griezel, © GIA)
Johannesburg—Three stones submitted to the Gemological Institute of America’s lab in Johannesburg, South Africa turned out to be moissanites inscribed with GIA report numbers belonging to natural diamonds.
It is a first such discovery for the laboratory.
GIA reported on the finding in the fall 2020 issue of Gems & Gemology, in an article in the Lab Notes section authored by Sicebiso Hlatshwayo and Sally Eaton-Magaña.
The note specifically addressed the first of the three stones received, a 1.02-carat round brilliant recently submitted for a Diamond Grading report.
Standard testing showed the stone was not a diamond, and further tests proved it to be a synthetic (lab-grown) moissanite, Hlatshwayo and Eaton-Magaña wrote.
They noted simulants are “often” submitted to the lab for diamond grading but are easily rooted out using the standard grading process.
This is the first time, however, the lab has come across a fraudulent inscription on a diamond simulant, and the fake was apparent to graders for a number of reasons.
It is a first such discovery for the laboratory.
GIA reported on the finding in the fall 2020 issue of Gems & Gemology, in an article in the Lab Notes section authored by Sicebiso Hlatshwayo and Sally Eaton-Magaña.
The note specifically addressed the first of the three stones received, a 1.02-carat round brilliant recently submitted for a Diamond Grading report.
Standard testing showed the stone was not a diamond, and further tests proved it to be a synthetic (lab-grown) moissanite, Hlatshwayo and Eaton-Magaña wrote.
They noted simulants are “often” submitted to the lab for diamond grading but are easily rooted out using the standard grading process.
This is the first time, however, the lab has come across a fraudulent inscription on a diamond simulant, and the fake was apparent to graders for a number of reasons.
The 1.02-carat round brilliant lab-grown moissanite that was inscribed with the report number for a natural diamond of the same weight (Photo by Innocentia Nzuza, © GIA)
First, GIA checks all stones with a pre-existing inscription.
The report number on the 1.02-carat round brilliant moissanite belonged to an E-color natural diamond of the same carat weight graded in 2019.
The measurements of the stones, however, were “quite different” due to the fact that the two materials have a different specific gravity, Hlatshwayo and Eaton-Magaña wrote.
The specific gravity of diamond is 3.52 while moissanite’s is 3.22, which means that moissanite, any moissanite, has to be slightly larger than a diamond to equal its carat weight.
“Since the specific gravity of moissanite is smaller than diamond, it is less dense and needs to have a larger volume for the same weight,” GIA explained in an email to National Jeweler.
In addition, the font used for the inscription on the moissanite was “distinctly different” from GIA’s usual font and, while GIA does not assign clarity grades to lab-grown moissanite, the stone in question is equivalent to a VVS2, while the clarity grade on the report for the natural diamond is VVS1.
The lab note in the fall edition of Gems & Gemology did not provide details on the other two lab-grown moissanite submitted with fraudulent inscriptions, as they did not come into the lab until after the article was written.
Those stones “were handled in a similar manner,” Hlatshwayo and Eaton-Magaña concluded.
More on Lab-Grown
The Latest
TrendsSep 12, 2025
Piece of the Week: Arunashi’s Fordite and Rhodolite EarringsFordite is a man-made material created from the layers of dried enamel paint that dripped onto the floors of automotive factories.
Events & AwardsSep 12, 2025
Al Gilbertson Wins 2025 Robert M. Shipley AwardGilbertson has worked as a researcher, jeweler, lapidary artist, appraiser, and business owner throughout his decades in the industry.
Brought to you by
reDollar.com Is Rolling Out the Next Level Jewelry, Diamond & Watch Consignment ProgramWith their unmatched services and low fees, reDollar.com is challenging some big names in the online consignment world.
Policies & IssuesSep 11, 2025
Supreme Court to Hear Tariffs Case in November A decision likely won’t come until January 2026 at the earliest, and the tariffs remain in effect until then.
Weekly QuizSep 12, 2025
This Week’s QuizTest your jewelry news knowledge by answering these questions.
MajorsSep 11, 2025
Tabayer Opens Nordstrom Shop-In-ShopLocated in the revamped jewelry hall at the retailer’s New York City flagship, this opening is Tabayer’s first shop-in-shop.
SourcingSep 11, 2025
Need to Sell More Natural Diamonds? De Beers Has an App for ThatThe new, free app offers accessible educational content, like games and podcasts, for U.S. retailers.
Brought to you by
Rallying Call for the Jewelry Industry on Tariffs and Other Key IssuesJewelers of America is leading the charge to protect the industry amidst rising economic threats.
MajorsSep 10, 2025
Stuller to Swap Gold Scrap for Full Credit to AccountAs the gold price rises, the manufacturer is offering a 100 percent payout through Sept. 30 for gold clean scrap.
SourcingSep 10, 2025
Tech Meets Style in the New Loewe x Jacob & Co. HeadphonesJacob & Co. partnered with the German technology company on two pairs of headphones, one set with diamonds and the other with sapphires.
TrendsSep 10, 2025
Tiffany & Co. Archival Jewels Bring Life to ‘Frankenstein’Guillermo del Toro’s 2025 “Frankenstein” will feature 27 jewels and objects from the storied brand, including pieces from its archives.
MajorsSep 10, 2025
24 Karat Club of New York’s Banquet to Return to Waldorf AstoriaThe Waldorf Astoria New York’s grand reopening this past summer means a homecoming for the industry group’s annual event.
SourcingSep 09, 2025
Anglo American to Merge With Canadian Copper Miner Anglo plans to merge with Teck Resources Ltd. to form Anglo Teck. The deal changes nothing about its plans to offload De Beers.
AuctionsSep 09, 2025
‘The Mellon Blue’ to Return to Auction, This Time at Christie’s The 9.51-carat fancy vivid blue diamond, which set two world auction records at Sotheby’s in 2014, is estimated to fetch up to $30 million.
AuctionsSep 09, 2025
Phillips Names Dianne Batista Head of Jewels, New YorkThe industry veteran joins the auction house as it looks to solidify its footprint in the jewelry market.
MajorsSep 09, 2025
MJSA Education Foundation Announces 2025 Scholarship WinnersThe nonprofit awarded four students pursuing a professional career in jewelry making and design with $2,250 each.
IndependentsSep 08, 2025
Take a Look Inside the New Korman Store in AustinThe Texas-based jeweler has also undergone a brand refresh, debuting a new website and logo.
MajorsSep 08, 2025
MJSA Is Officially Now Under JA’s UmbrellaThe two organizations have finalized and signed the affiliation agreement announced in May.
AuctionsSep 08, 2025
Sotheby’s To Auction ‘Exceptional’ Collection of JAR, Suzanne Belperron JewelsThe single-owner sale will headline Sotheby's inaugural jewelry auction at the Breuer building, its new global headquarters, this December.
Events & AwardsSep 08, 2025
27 Can’t-Miss Converge Sessions, Events From sunrise yoga to tariffs talks, these are some events to check out at the upcoming inaugural event.
ColumnistsSep 05, 2025
Peter Smith: A Lasting Lesson From Maurice Tempelsman Smith recalls a bit of wisdom the industry leader, who died last week, shared at a diamond conference years ago.
CollectionsSep 05, 2025
Piece of the Week: Jamie Turner’s ‘Victoria’ Necklace The “Victoria” necklace features a labradorite hugged by diamond accents in 18-karat yellow gold.
Policies & IssuesSep 05, 2025
Trump Takes Tariffs Case to the Supreme Court Two lower courts have moved to block the import taxes, which will remain in place as the legal battle continues.
WatchesSep 05, 2025
Patrick Mahomes Is the New Hublot Brand AmbassadorThe Kansas City Chiefs quarterback shares Hublot’s dedication to pursuing greatness, the Swiss watchmaker said.
SourcingSep 04, 2025
Lucara Unveils Unusual 37-Carat Pink DiamondThe Type IIa stone, recovered from Botswana’s Karowe diamond mine last month, features unique coloration.
WatchesSep 04, 2025
Breitling Takes Its NFL Game to the Next Level Breitling is now the NFL’s official timepiece partner, a move that puts the brand in front of the millions of Americans who watch football.
