Grading

Lead Glass-Filled Lab-Grown Ruby Submitted to GIA

GradingJul 23, 2021

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.

20210723_GIA-header.jpg
A 3.53-carat lab-grown ruby treated with lead-glass filling (Photo by Diego Sanchez; © GIA)
Carlsbad, Calif.—GIA recently received a stone it rarely sees: a lead glass-filled lab-grown ruby.

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.

20210723_GIA-insert.jpg
Putting the lab-grown ruby under magnification revealed high relief trapped gas bubbles and blue and orange flash effects. (Photomicrograph by Diego Sanchez, field of view 7.19 mm; © GIA)

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.”

 Related stories will be right here … 

The Latest

Pantone color of the year 2024
TrendsDec 08, 2023
Pantone’s Color of the Year Is Warm and Fuzzy

The peachy hue also marks the program’s 25th anniversary.

Mary Tyler Moore and Elsa Peretti for Tiffany & Co. Bone Cuffs
AuctionsDec 08, 2023
Sotheby’s Sold All Mary Tyler Moore’s Jewelry

The 21 pieces up for auction, including Tiffany & Co. jewels and a Cartier watch, garnered more than $430,000 across two sales.

Inesa Kovalova’s Links pin
CollectionsDec 08, 2023
Piece of the Week: A ‘Strong & Precious’ Brooch

Centered on a sunny heliodor, the “Links” pin was designed by Ukrainian jewelry artist Inesa Kovalova.

De Beers | Diamonds Falling
Brought to you by
The Most Important “C” in Diamonds: Confidence!

Without the ability to instill confidence within the industry and directly to the consumer, a diamond holds very little value.

Lashbrook ring
MajorsDec 07, 2023
Lashbrook Sues Manly Bands for Allegedly Copying Designs

The wedding band company is also accusing its former customer of removing watermarks from Lashbrook images for its own use.

Weekly QuizDec 07, 2023
This Week’s Quiz
Test your jewelry news knowledge with this short test.
Take the Quiz
Rough diamonds from Alrosa
Policies & IssuesDec 07, 2023
The G7’s Long-Awaited Statement on Russian Diamonds Is Here

It provides a timeline for the implementation of new restrictions, but no details.

24 Karat Club of New York new members
MajorsDec 07, 2023
24 Karat Club of New York Welcomes New Members

The organization has elected 12 new additions.

Platinum  Guild International Diamond Rings
Brought to you by
If It’s Custom, Make It Platinum

With holiday proposals right around the corner, encourage your customers to go for platinum when making the big purchase.

National Jeweler columnist Sherry Smith
ColumnistsDec 06, 2023
On Data: How Are Independents Doing So Far This Holiday Season?

Sherry Smith breaks down the numbers on jewelry sales in November and reveals the category that “emerged as a standout.”

133 carat yellow diamond
AuctionsDec 06, 2023
A Yellow Diamond, Hollywood Jewels Stand Out at Sotheby’s

Additional lots will be offered in the Fine Jewels online sale through Dec. 7.

A 1930s gem-set and enamel ‘Maltese cross’ cuff attributed to Verdura for Chanel (left) and a loose cushion-cut Burmese sapphire weighing 11.87 carats (right) were the top lots in Bonhams New York Jewels auction this week.
AuctionsDec 06, 2023
Verdura Cuff, Burmese Sapphire Shine at Bonhams

Several other colored gemstones joined the pieces in the top 10 list.

Neil Lane lab-grown diamond engagement ring
FinancialsDec 05, 2023
Signet Jewelers’ Q3 Sales Down 12%

The retailer is still expecting a strong holiday season with improving demand for natural diamonds.

Memorial for slain jeweler Peter Damian Arguello in Wheat Ridge, Colorado
CrimeDec 05, 2023
Police Continue to Investigate Murder of Colorado Jeweler

Peter Damian Arguello, the owner of Peter Damian Fine Jewelry & Antiques, was shot and killed in an apparent robbery last week.

Tanishq store
MajorsDec 05, 2023
Tanishq Continues U.S. Expansion With 2 New Stores

The Indian jewelry giant has opened locations in Houston and Frisco, Texas.

Grandview Klein Diamonds Namibia scholarship winners
SourcingDec 05, 2023
Grandview Klein Awards Two Scholarships in Namibia

Each student was provided with the full amount of tuition for the Namibia University of Science & Technology.

De Beers Ryan Perry and David Prager
SourcingDec 04, 2023
David Prager To Leave De Beers in 2024

Ryan Perry, who has been with De Beers since 2002, also will be leaving the company next year.

Chrono24 ChronoPulse
WatchesDec 04, 2023
Chrono24 Debuts the ‘Dow Jones’ for Luxury Watches

The watch seller’s new index tracks sales data from 14 brands, including Rolex and Patek Philippe.

David Bouffard Signet Jewelers
MajorsDec 04, 2023
David Bouffard to Leave Signet, RJC

The industry veteran will step down from both roles in April 2024.

David Webb turquoise and lapis ring
TrendsDec 04, 2023
Amanda’s Style File: Decadent December

Tanzanite, turquoise, and zircon are all options for December babies, who sometimes “get the birthday shaft,” Amanda Gizzi writes.

Lightbox x Roséate Light Wand pendants
Lab-GrownDec 01, 2023
Lightbox Teams Up With Brand Founded by Former Tiffany Exec

The lab-grown diamond brand also collaborated with the website The Future Rocks on a collection launching today.

Lila Moss Calvin Klein campaign
FinancialsDec 01, 2023
Movado Lowers Guidance Again After Q3 Sales Dip

The company said it is facing a “challenging retail environment” but is prepared for the holiday season.

Muzo emerald and argyle pink diamond necklace
CollectionsDec 01, 2023
Piece of the Week: Muzo’s Emerald and Argyle Pink Diamond Necklace

It’s the hero piece of the newest "Green Jewel" collection, a collaborative offering from the two mines.

Pink Supreme Diamond
AuctionsNov 30, 2023
This Pink Diamond Reigned Supreme in Hong Kong

The 15.48-carat fancy intense “Pink Supreme” topped Christie’s fall jewelry auction in Asia, while a Patek Philippe led the watch sale.

Claire’s CFO COO Chris Cramer
MajorsNov 30, 2023
Claire’s Hires Former Bath & Body Works Exec as CFO, COO

Chris Cramer, who also spent time at Gen Z intimates brand Parade, will take on the dual role.

133 carat yellow diamond
AuctionsNov 30, 2023
Sotheby’s To Auction 133-Carat Yellow Diamond

The stone headlining the upcoming sale could fetch up to $5 million.

Kwiat diamonds
IndependentsNov 30, 2023
Frank Adams Rolls Out Kwiat’s ‘Mine to Shine’ Program

The retail offering lets customers track their diamond’s journey.

Diamond development hub in Angola
SourcingNov 29, 2023
Largest New Diamond Mine of the Decade Coming Online in Angola

The Luele mine is expected to eventually make the country the world’s third-largest diamond producer.

×

This site uses cookies to give you the best online experience. By continuing to use & browse this site, we assume you agree to our Privacy Policy