GIA Finds Lab-Growns, Simulant in Parcel of ‘Natural’ Sapphires
It offered a look at how synthetics and simulants “can be mixed with their natural counterparts to misrepresent a parcel,” the lab said.
According to a lab note written by Najmeh Anjomani in GIA’s Summer 2022 Gems & Gemology issue, its Carlsbad lab recently received four rough blue stones submitted as natural sapphires for identification and origin reports.
The largest weighed 48.63 carats. It was partially fashioned, GIA said, with evidence of polish lines on its surface.
Examination under a microscope revealed gas bubbles, distinct flow marks, and conchoidal fractures, while the polariscope revealed weak snake pattern bands. Its hydrostatic specific gravity (SG) was 2.48.
All these observations together suggested a glass imitation, GIA said, which was confirmed by comparing the infrared spectrum with that of man-made glass.
Two of the other submitted blue stones, weighing 9.17 carats and 6.21 carats, were “more convincing imitations of natural sapphire,” GIA said.
There was a resin coating their surfaces that resembled a matrix commonly seen on natural rough corundum. GIA said the resin started to melt when touched with a hot point.
And though their rough surfaces made it difficult to see inside the stones, GIA was able to observe a few gas bubbles through a transparent area.
It also performed Raman spectroscopy, the results of which matched corundum, and immersed the stones in water, revealing curved blue banding.
GIA said laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) revealed trace elements matching synthetic corundum. SG values were found to be 3.76 and 3.59, respectively, both of which are below the SG of corundum (3.9-4.05) and are a result of the lower SG of the surface resin.
The lab issued reports for both identifying them as lab-grown sapphires.
Finally, the fourth rough blue stone submitted weighed 8.46 carats.
It had a “frosted” natural surface that made it hard to see inside, but GIA said it was able to observe some natural-looking fingerprints and strong, straight “inky” blue banding.
The lab immersed the stone in methylene iodide to confirm the color zoning it saw was straight, an indication of a natural origin.
The Raman spectrum matched that of corundum, further confirmed by SG of 3.96.
GIA put the stone under shortwave UV and saw a medium chalky blue fluorescence.
LA-ICP-MS revealed a natural chemistry, including iron and trace elements such as gallium, vanadium, magnesium, chromium, and titanium.
Given its appearance, color zoning, and chemistry, the stone was identified as a natural sapphire, with its report noting it had been heated and was of Madagascar origin.
Anjomani said in the lab note that the four submitted stones provided an “interesting study of how synthetics and simulants can be mixed with their natural counterparts to misrepresent a parcel.”
The author noted, however, that “careful examination and standard gemological testing are usually enough to identify them correctly.”
The Latest
Starboard Luxury is bringing the Italian brand aboard The Ritz-Carlton Yacht Collection’s newest yacht.
The pendant, circa the late 1700s, likely was commissioned to remember a loved one who died young.
It features the brand’s products in the precious color, semi-precious color, pearl, diamond, gold, and sterling silver categories.
From protecting customer data to safeguarding inventory records, it's crucial to learn how to tackle cybersecurity challenges.
For her annual Halloween story, Associate Editor Lenore Fedow pairs fine jewelry with classic and contemporary Halloween costumes.
Sales fell 15 percent for the luxury conglomerate in the third quarter, led by a 26 percent drop in sales for flagship brand Gucci.
The education offerings include a diamond cutting demonstration, a session with JVC President Sara Yood, and a seminar on AI.
This fall, sharpen your skills in jewelry grading, quality control and diamond assessment.
The book features new styles and revived favorites.
Aimed at a generation that emphasizes self-care and mental health, “Worth the Wait” breaks new ground in the world of diamond advertising.
Editor Lauren McLemore immersed herself in New York Bridal Fashion Week to better understand the role fine jewelry plays on the big day.
The jeweler shared her change of heart on lab-grown diamonds and why she keeps them separate from natural diamonds in her business ventures.
The New York-based brand is expanding outside of the U.S., with a pop-up shop in London and plans to distribute internationally.
They’re available through a retailer that sells luxury products inspired by the lifestyle of Batman’s billionaire civilian persona.
The watchmaker is selling 1,000 “Waterbury” watches for $1 each in celebration of its 170th anniversary.
Launched by De Beers in 2018, the program aims to develop a responsible sourcing model for the artisanal/small-scale diamond mining sector.
The new “Ouche” collection brings sculptural designs to the brand, while the expanded “Daystar” collection brings a rainbow of colors.
The auction house said the gemstone could fetch up to $5.5 million at next month’s sale.
From prioritizing the customer experience to optimizing inventory, columnist Emmanuel Raheb shares the keys to a successful holiday season.
Journalist Priya Raj plans to use the scholarship funds to further her media qualifications and amplify marginalized communities.
It marks the first championship win in the team’s 28-year history.
The Arkansas-based jeweler’s first store in the state’s northwest region is set to open next year.
It will start with rough diamonds that are larger than 1.25 carats and later expand to rough diamonds that are above 1 carat.
The capsule collection is inspired by friendship and connection, with a nod to ‘80s fashion.
The New York socialite’s elegant, transformable piece from the 1960s is headed to auction later this month.
Texas jeweler Susan Eisen and NAJA’s Gail Brett Levine discuss how lab-grown diamonds have altered the landscape for jewelry appraisers.
On the verge of retirement, Kennedy recounts the most stressful stretch of his time at JSA and reveals what he’ll miss about the industry.