Grading

GIA Finds Imitation Emerald Made of Layered Glass

GradingAug 23, 2018

GIA Finds Imitation Emerald Made of Layered Glass

The 3.35-carat stone had a natural beryl core; glass layers were attached to it with a “colorless cement.”

20180823_GIA-Header.jpg
A face-up view of the imitation emerald under cross-polarized light showing the inert reaction of the outer material and interference planes that outline the beryl core (Photomicrograph by Tyler Smith, GIA)

New York—Another gem has surfaced at a lab that was not entirely what it seemed.

A 3.35-carat “emerald” submitted to the Gemological Institute of America’s New York lab turned out to be an assembled imitation gemstone composed of five layers of glass cemented to a beryl core, according to an article by Tyler Smith and Augusto Castillo in the Summer 2018 issue of Gems & Gemology.

The rectangular core was a natural beryl, the mineral species to which emerald belongs, but the crown was a single piece of glass attached to the pavilion, while the pavilion was composed of four asymmetrical glass segments glued to the core using a “colorless cement.”

The imitation stone probably took a while to create using a “laborious multistep cut-and-glue process,” GIA authors said, as indicated by the way the four glass segments in the pavilion are interlocked.


When viewed face up, the imitation emerald showed the natural inclusions seen underneath the table as well as large bubbles visible at the corners of the beryl core. (Photo by Jian Xin (Jae) Liao, GIA)
The manufacturing of the piece started by attaching a glass segment to the beryl core. Both were then cut to create a flat surface for a second piece of glass. The second was then added, cut to allow for the third, and so forth.

After all four had been added, the assembled pavilion likely would have been polished flat to allow for the crown, which then would have been attached.

(Check out the original lab note from GIA for a diagram showing the process.)

The article also noted that while assemblages of various materials have long been used to imitate precious stones—with the most common kind using two or more pieces joined together in parallel, layered fashions—GIA researchers weren’t able to find record of another stone assembled using the process applied to this “emerald.”

RELATED CONTENT: Glued-Together Diamond Turns Up at GIA
GIA said it was the first time one such assembled stone has been submitted to its New York or Carlsbad laboratories.

Researchers surmise that the imitation emerald was created relatively recently, given the fact that all its exposed surfaces are made of glass and, yet, the facet junctions are still sharp and the stone lacks wear.

“It is intriguing that an antiquated technique is updated in modern times, serving as a cautionary tale of the ingenuity counterfeiters employ,” the authors said.
Brecken Branstratoris the senior editor, gemstones at National Jeweler, covering sourcing, pricing and other developments in the colored stone sector.

The Latest

Edahn Golan, Tenoris co-founder and National Jeweler contributor
ColumnistsMay 18, 2026
Edahn Golan: What a K-Shaped Economy Means for Fine Jewelry

In a column for the 2026 State of the Majors issue, Golan spells out how the growing economic divide in the U.S. is reshaping the market.

Foundrae Limitless Expansion of Joy and Hope Collection Campaign Imagery
CollectionsMay 18, 2026
Foundrae’s New Collection Taps Into Joy

The “Limitless Expansion of Joy and Hope” collection evokes summer through colored gemstones and motifs of butterflies and florals.

Inchiquin emerald
CollectionsMay 18, 2026
Hancocks London Acquires Historic ‘Inchiquin’ Emerald

The jewel, circa 1890, is from the late Victorian era and was owned by descendants of the last high king of Ireland.

1872x1052-NextGem-2026-National-Jeweler-Advertorial.jpg
Brought to you by
How Modern Training Is Becoming a Competitive Advantage for Jewelry Retailers

With the trade and customer trust in mind, GIA® developed NextGem™ – on-demand training designed specifically for retail.

JCK Industry Fund Logo
Events & AwardsMay 18, 2026
Here Are the 2026 JCK Industry Fund Grant Recipients

This is what the nine recipients plan to do with the funds.

Weekly QuizMay 14, 2026
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
John Wayne Signet Ring
AuctionsMay 15, 2026
American Collector Ponies Up Almost $17K for John Wayne’s Ring

The Western star’s 14-karat gold signet ring sold for six times its low estimate following a bidding war at U.K. auction house Elmwood’s.

MJSA Education Foundation and Jewelers of America
Events & AwardsMay 15, 2026
JA, MJSA To Sponsor Roundtable at TJS

The discussion, "Rebuilding the Jewelry Workforce," will take place on Saturday, May 16, in Troy, Michigan.

Antique Jewelry & Watch Show
Brought to you by
Discover Timeless Treasures: A Showcase of Antique Jewelry & Timepieces in Las Vegas

Gain access to the most exclusive and coveted antique pieces from trusted dealers during Las Vegas Jewelry Week.

Three gold rings set with yellow- and brown-hued diamonds
SourcingMay 15, 2026
State of Diamonds: The Way Forward for Natural Diamonds

The jewelry industry is reassessing its positioning as Gen Z reshapes the retail landscape and lab grown continues to gain market share.

Matching pair of Type IIa, D-color diamonds
AuctionsMay 14, 2026
White Diamonds Lead Sotheby’s Auction, Blue Diamond Does Not Sell

A matching pair of 18.38-carat, D-color diamonds from Botswana’s Jwaneng mine sold for $3.3 million, the top lot of the jewelry auction.

DeBeeers_Bridal_Display_Dune_1872x1052.jpg
Supplier BulletinMay 14, 2026
A Diamond Is Forever Continues Desert Diamonds – Bridal Reinvigorated

Sponsored by A Diamond Is Forever

Faceting Apprentice gem cutting school
SourcingMay 14, 2026
State of Colored Stones: The Spirit of Young American Gemstone Cutters

The next generation of lapidarists are entrepreneurial, engaged online, and see the craft as a means for artistic expression.

Ocean Dream diamond
AuctionsMay 14, 2026
‘Ocean Dream’ Makes Waves at Christie’s, Fetching $17M

It was the second auction appearance for the fancy vivid blue-green diamond, which sold for $7.8 million at Christie’s Geneva 12 years ago.

Stock image of police cars with their lights on
CrimeMay 14, 2026
Second Man Arrested in Florida Pawn Shop Shooting

Members of the U.S. Marshals Task Force took a 22-year-old man into custody. He was charged with tampering with evidence.

Stock image of crime scene with police cars and crime scene tape
CrimeMay 13, 2026
JSA’s 2025 Crime Report Shows ‘Concerning’ Rise in Violence

While the overall number of crimes was down, there were more incidences in which robbers pulled out guns, mace, or rammed cars into stores.

Jack Sutton Jewelers
IndependentsMay 13, 2026
New Orleans Jeweler Closing Canal Place Store

Jack Sutton Fine Jewelry is closing its store inside the downtown shopping center after 40 years in business.

Winston Red Diamond painting by Reena Ahluwalia
SourcingMay 13, 2026
Smithsonian Acquires ‘Winston Red’ Diamond Painting

Reena Ahluwalia’s painting of the rare red diamond is the first contemporary painting to join the National Gem Collection.

Anna Maccieri Rossi Ora Wood Sunrise Cuff, Marie Lichtenberg High Jewelry Bandana, Anna Maccieri Rossi Carpe Diem Pendant
TrendsMay 13, 2026
State of Design: Only the Innovative Will Survive

The price of gold has risen, affecting the number of pieces designers make, the materials they use, and how they position themselves.

The Retail Smiths founder and National Jeweler columnist Peter Smith
ColumnistsMay 12, 2026
It’s Official: We’re Getting ‘Brain Rot’ From Watching Short-Form Videos

Peter Smith gives tips on leading meetings, developing marketing, and making trade show appointments in the age of short attention spans.

Jessica McCormack Medallion Capsule Collection Campaign
CollectionsMay 12, 2026
Jessica McCormack Debuts Antique Coin-Inspired Medallions for Summer

The 11-piece “Medallions” capsule collection features five motifs: a crying eye, a heart on fire, a spiral, a flower, and a swallow.

People shopping in a jewelry store
IndependentsMay 12, 2026
State of Retail: 6 Things Retailers Should Know About Consumers Today

From Gen Z’s view of luxury to “doom spending,” these are the six consumer trends to note this year.

Tiffany & Co. x CFDA Jewelry Designer Award
Events & AwardsMay 12, 2026
The Tiffany & Co. x CFDA Jewelry Designer Award Is Back

The partners have announced the second cycle of the program, which has expanded to include a $25,000 student scholarship.

Merle, Juanita, and Brent Staats of Staats Jewelers
IndependentsMay 11, 2026
Kansas Jeweler Closing After 70 Years

The owners of Staats Jewelers are heading into retirement.

Former Macy’s CEO Jeffrey Gennette
TrendsMay 11, 2026
Former Macy’s CEO Joins Signet Jewelers Board

Jeffrey Gennette, who retired in 2024 after 41 years with Macy’s, is the newest member of the jewelry retailer’s board of directors.

Buddha Mama gold earrings hexagon emerald
TrendsMay 11, 2026
Amanda’s Style File: Lucky May

May babies are lucky to have emeralds, a gemstone admired for centuries, as their birthstone, writes Amanda Gizzi.

Clientbook Logo
TechnologyMay 11, 2026
Clientbook’s New Tool Helps Jewelers Plan In-Store Events

The new module allows retailers to plan, promote, and measure the success of events from a single dashboard.

Pandora lab grown diamond necklace
Lab-GrownMay 08, 2026
NDC Publicly Criticizes Pandora Over ‘Misleading’ Natural Diamond Claims

NDC said in an open letter that Pandora’s statements about the carbon footprint of lab grown versus natural diamonds are inaccurate.

×

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