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
The announcement coincided with its full-year results, with growth driven by its jewelry brands.
Looking ahead, the retailer said it sees “enormous potential” in Roberto Coin’s ability to boost its branded jewelry business.
Jewelry trade show veterans share strategies for engaging buyers, managing your time effectively, and packing the right shoes.
Despite the rising prices, consumers continue to seek out the precious metal.
This little guy’s name is Ricky and he just sold for more than $200,000 at Sotheby’s Geneva jewelry auction.
Though its website has been down for a week, Christie’s proceeded with its jewelry and watch auctions on May 13-14, bringing in nearly $80 million.
Despite the absence of “The Allnatt,” Sotheby’s Geneva jewelry auction totaled $34 million, with 90 percent of lots sold.
Tradeshow risks are real. Get tips to protect yourself before, during and after and gain safety and security awareness for your business.
Lilian Raji gives advice to designers on how to make the most of great publicity opportunities.
The mining company wants to divest its 70 percent holding in the Mothae Diamond Mine in an effort to streamline its portfolio.
Why do so many jewelers keep lines that are not selling? Peter Smith thinks the answer lies in these two behavioral principles.
The “Argyle Phoenix” sold for more than $4 million at the auction house’s second jewels sale.
The annual list recognizes young professionals making an impact in jewelry retail.
Owner David Mann is heading into retirement.
While overall sales were sluggish, the retailer said its non-bridal fine jewelry was a popular choice for Valentine’s Day.
The mining giant also wants to offload its platinum business as part of an overhaul designed to “unlock significant value.”
Christie's is selling one of the diamonds, moving forward with its Geneva jewelry auction despite the cyberattack that took down its website.
The ad aims to position platinum jewelry as ideal for everyday wear.
The move follows a price-drop test run in Q4 and comes with the addition of a “quality assurance card” from GIA for some loose diamonds.
The site has been down since Thursday evening, just ahead of its spring auctions.
The late former U.S. Secretary’s collection went for quadruple the sale’s pre-sale estimate.
Three fifth graders’ winning designs were turned into custom jewelry pieces in time for Mother’s Day.
Kimberly Adams Russell is taking over the role from her father, David Adams, marking the third generation to hold the title.
As a token of womanhood, this necklace depicts when Venus was born from the sea.
The deal gives the retailer control over the distribution of Roberto Coin jewelry in the U.S., Canada, Caribbean, and Central America.
Show your mother some love with a piece of fine jewelry.
The company’s Easton location will remain open.