Lead Glass-Filled Lab-Grown Ruby Submitted to GIA
Though it’s unclear why someone would treat the material in that way, it’s important gemologists know it exists, the lab said.
According to a lab note from Forozan Zandi in the spring 2021 issue of “Gems & Gemology,” the stone was submitted to the GIA Carlsbad lab for identification.
Zandi said that while it’s common for the lab to receive lead glass-filled natural rubies, to their knowledge only one other lab-grown example has ever been submitted.
The recently submitted ruby was transparent to semi-transparent, oval mixed-cut, and weighed 3.53 carats.
GIA performed the standard gemological tests on the stone, finding that it showed the properties of a ruby, including a refractive index of 1.761–1.769, a birefringence of 0.008, a specific gravity of 4.01, a uniaxial optic figure, and a characteristic ruby spectrum via a spectroscope.
It also put the stone under magnification, which helped the lab confirm it was filled, according to the note.
With lead glass-filled corundum, the filling material has a refractive index very close to that of the host material to reduce the appearance of fractures. GIA said it’s effective and helps improve clarity of even very low-quality material to help make it marketable.
Fortunately, it’s also easily detected under magnification, the lab added.
The lab-grown ruby in question showed a couple of conclusive identifying characteristics for the treatment when put under the microscope: orange and blue flash effects and gas bubbles trapped in the fractures.
Magnification, however, didn’t reveal any inclusions that would indicate a natural or lab-grown origin.
But when it viewed curved growth lines in the DiamondView, which looks at surface fluorescence by illuminating with shortwave ultraviolet light, the lab saw the striae as chalky luminescent bands, confirming the stone was lab grown.
Ultimately, the lab note concluded: “While it is unclear why anyone would go to the trouble to treat a synthetic ruby with lead-glass filling, gemologists should be aware that such material does exist in the trade.”
The Latest
Drosos shared her top takeaways from a recent Botswana trip and her insights into the natural diamond market.
The retailer is expanding its footprint via retail partnerships, previously inking deals with Kohl’s and Macy’s.
Members will now have access to “eBay Concierge,” a white-glove dedicated customer service team.
Ho Brothers offers scalable solutions for the future of custom jewelry.
The deadline to apply is March 29.
CEO Beth Gerstein spoke about the growing appeal of its non-bridal fine jewelry and its expansion plans on its recent earnings call.
Ticketholders can dig for diamonds in the Arkansas park ahead of the eclipse viewing event on April 8.
Distinguishing natural diamonds from laboratory-grown stones – now more available than ever – has been difficult for jewelers. Until now.
The versatile jewel pairs ancient Egyptian inspiration with a modern design.
The company’s rough sales improved for the third sales cycle in a row.
It’s estimated to sell for up to $1.3 million at the upcoming sale on March 28.
It aims to support aspiring journalists, media professionals, content creators, and communicators.
“Ice Cold: An Exhibition of Hip-Hop Jewelry” will open at the New York City museum on May 9.
He succeeds David Bouffard, who is leaving Signet and the RJC next month.
Three winners will have their jewelry sketches turned into a real piece of jewelry in time for the holiday.
“Power of Couture” recalls Frédéric Boucheron’s love of fabric using diamonds and rock crystal.
A Harry Winston diamond necklace and other top lots failed to find buyers.
Lilian Raji offers advice to a business owner who is having trouble crossing the finish line with customers.
He brings 30 years of retail store management experience to the role.
At its annual gala, Diamonds Do Good will present awards to GIA, London Jewelers, and Lisa Bridge.
Vibrant gemstones, layered diamond pieces and brooches with a story stole the show.
The 2024 winners expressed gratitude to their teams, industry colleagues, and those who turn jewelry dreams into reality.
They are Marla Aaron, Marie Lichtenberg, and Jean Prounis.
The Jewelers’ Security Alliance will honor the industry veteran at its upcoming annual luncheon.
The annual video stars Pomellato CEO Sabina Belli alongside Jane Fonda and other celebrities and activists.
Sponsored by IGI
The Pennsylvania native, who sold for Gumuchian and others, is remembered for being kind and outgoing.