Editors

A Hands-on Lesson in Telling Gemstones Apart

EditorsApr 18, 2016

A Hands-on Lesson in Telling Gemstones Apart

Senior Editor Brecken Branstrator recounts what she learned at an AGS Conclave education session on identifying gemstones presented by Gem-A.

20160418_GemA-Article.jpg

The American Gem Society knocks it out of the park every year for their Conclave event. The keynote speakers are top-notch, and the education sessions cover a wide variety of topics presented by experts in the industry.

Held in Washington, D.C. this year, Conclave again was full of great sessions, from a panel on bridal trends, to updates on diamond prices and grading reports, to a fascinating session on diamonds and their healing powers.

A particularly cool one that I got to attend was held Friday by The Gemmological Association of Great Britain (Gem-A).

In “Separating Similar-Looking Stones,” Gem-A’s Claire Mitchell began by walking session attendees through the steps used to identify a stone, starting with observation and then working through the instruments that can help jewelers tell apart similar-looking stones.

I loved this session because it was a hands-on experience--half the session was a presentation and the other half had us using the instruments ourselves. (I think a lot of people were excited about this session, as it had a waiting list and attendees were lined up before it started. I was lucky enough to just make it in and get a seat with equipment.)

First, Mitchell walked us through what kind of observations can be made before using any instruments.

For example, inclusions such bubbles and swirls or molding marks that indicate a paste glass might tell you that a gemstone is man-made.

Inclusions in natural stones can help indicate what the stone might be as well, such as “horsetail inclusions” found in demantoid garnets or “lily pads” that show up in peridot.

Next, Mitchell walked us through the use of instruments such as a polariscope, spectroscope and a dichroscope.

We got to use all three on gemstone samples provided so we could see for ourselves how each worked and what the stones looked like through the instruments.

The polariscope, for example, can tell you if a stone has double or single refraction, while a spectroscope is a diagnostic tool showing a spectrum of colors that is “like having a bar code for a gemstone” to help with identification.

My personal favorite was the Chelsea Color Filter, which is a dichromatic filter that transmits two wavelengths only to help identify certain green, red and blue stones, as well as detecting dyes in certain gems.

Above is a picture of three different blue stones--aquamarine, topaz and spinel--under the filter.

I
love any opportunity that allows me the chance to learn more about stones, and the sentiment in the room seemed to indicate that everyone else found the session as useful as I did.

While I’m always trying to see if I can guess what a gemstone is when I see it, Gem-A stressed that there should always be more tests involved to figure out a stone’s true identity. This session definitely made me want to go out and get some of these instruments for myself.
Brecken Branstratoris the senior editor, gemstones at National Jeweler, covering sourcing, pricing and other developments in the colored stone sector.

The Latest

Marie Lichtenberg Lasso Locket Bracelets Campaign
CollectionsJan 14, 2026
Marie Lichtenberg Lassos Leather for New Bracelets

The brand is trading its colorful fabric cords for Italian leather in its “Lasso” baby locket bracelets.

“My Next Question: The Podcast” graphic featuring Amanda Gizzi and Michelle Graff
TechnologyJan 14, 2026
“My Next Question” Enters Its Podcast Era

National Jeweler and Jewelers of America’s popular webinar series is evolving in 2026.

Saks New York City holiday lights
MajorsJan 14, 2026
Saks Files for Bankruptcy, Names New CEO

The department store chain owes millions to creditors like David Yurman, Roberto Coin, Kering, and LVMH.

JamAlert 1872x1052.png
Brought to you by
How Jewelers Can Fight Back Against Cell Jammers

Criminals are using cell jammers to disable alarms, but new technology like JamAlert™ can stop them.

Colman Domingo
CollectionsJan 14, 2026
Boucheron Names Colman Domingo as Brand Ambassador

The award-winning actor’s visionary approach and creativity echo the spirit of Boucheron, the brand said.

Weekly QuizJan 08, 2026
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Burnell’s Fine Jewelry Kristi Regan, Nathan Regan, Sean Hamlin, Erin Carson
IndependentsJan 14, 2026
Kansas Jeweler Wins 2025 ‘Wag’ Award

Edge Retail Academy honored Burnell’s Fine Jewelry in Wichita, Kansas, with its annual award for business excellence.

National Jeweler columnist Sherry Smith, vice president of coaching strategy and development at the Edge Retail Academy
ColumnistsJan 13, 2026
2025 Was a ‘Price Up, Units Down’ Year, Here’s What That Signals for 2026

In a market defined by more selective consumers, Sherry Smith shares why execution will be independent jewelers’ key to growth this year.

Recipients Collage 2025 - NJ (1872 x 1050 px) (1872 x 1052 px).png
Brought to you by
Impacting Tomorrow Today

How Jewelers of America’s 20 Under 40 are leading to ensure a brighter future for the jewelry industry.

Orr’s Jewelers David Gordon, Marcia Gordon, Aliza Gordon, Leslie Gordon
IndependentsJan 13, 2026
Orr’s Jewelers Opens New Location in Pittsburgh’s Strip District

The family-owned jeweler’s new space is in a former wholesale produce market.

Stock image of a gavel and books
CrimeJan 13, 2026
Alleged Getaway Driver Charged in Florida Jewelry Store Robbery

Ivel Sanchez Rivera, 52, has been arrested and charged in connection with the armed robbery of Tio Jewelers in Cape Coral, Florida.

Rio Grande diamonds
SourcingJan 13, 2026
Rio Grande To Offer Calibrated Diamond Melee

The supplier’s online program allows customers to search and buy calibrated natural and lab-grown diamond melee, including in fancy shapes.

Hana Kaneko rings
Events & AwardsJan 13, 2026
NYC Jewelry, Antique, & Object Show Announces Winter Event

The new show will take place Jan. 23-25, 2026.

MNQ FINAL - NJ web - 1872 x 1052 px.png
PodcastsJan 12, 2026
Introducing My Next Question, the Podcast

A monthly podcast series for jewelry professionals

Peter Yanzter, former executive director of AGS Labs
GradingJan 12, 2026
Peter Yantzer, Former Executive Director of AGS Labs, Dies at 77

Yantzer is remembered for the profound influence he had on diamond cut grading as well as his contagious smile and quick wit.

Macy’s New York Herald Square
MajorsJan 12, 2026
These 14 Macy’s Locations Will Close This Year

The store closures are part of the retailer’s “Bold New Chapter” turnaround plan.

Jewelers Mutual logo
MajorsJan 12, 2026
Jewelers Mutual Acquires AI-Powered Event Insurance Program

Through EventGuard, the company will offer event liability and cancellation insurance, including wedding coverage.

Kendra Scott CEO Chris Blakeslee
MajorsJan 09, 2026
Kendra Scott Taps Activewear Exec as CEO

Chris Blakeslee has experience at Athleta and Alo Yoga. Kendra Scott will remain on board as executive chair and chief visionary officer.

Wrapped holiday present boxes
SurveysJan 09, 2026
U.S. Holiday Retail Sales Up 4%, Visa, Mastercard Say

The credit card companies’ surveys examined where consumers shopped, what they bought, and what they valued this holiday season.

Christie’s Kimberly Miller
AuctionsJan 09, 2026
Christie’s Names New Global Managing Director for Luxury

Kimberly Miller has been promoted to the role.

Lionheart Serenity Opal Amulet Charm
CollectionsJan 09, 2026
Piece of the Week: Lionheart’s ‘Serenity’ Opal Charm

The “Serenity” charm set with 13 opals is a modern amulet offering protection, guidance, and intention, the brand said.

Hannah Dodd and Claudia Jessie in Pandora Bridgerton campaign
CollectionsJan 08, 2026
Pandora’s New ‘Bridgerton’ Jewels Celebrate Bees, Bows, and Blooms

“Bridgerton” actresses Hannah Dodd and Claudia Jessie star in the brand’s “Rules to Love By” campaign.

Ana Khouri logo
Events & AwardsJan 08, 2026
Ana Khouri To Receive 2026 Gem Award for High Jewelry Excellence

Founded by jeweler and sculptor Ana Khouri, the brand is “expanding the boundaries of what high jewelry can be.”

Stuller’s Color of the Year for 2026, “Signature Red”
TrendsJan 08, 2026
Stuller’s Color of the Year Is a Stark Contrast to Pantone’s White

The jewelry manufacturer and supplier is going with a fiery shade it says symbolizes power and transformation.

Gracie Abrams Chanel Coco Crush
CollectionsJan 08, 2026
Gracie Abrams To Front New Chanel Jewelry Campaign

The singer-songwriter will make her debut as the French luxury brand’s new ambassador in a campaign for its “Coco Crush” jewelry line.

Bobbi L. Avery, Jeffery Bolling, Britney Phillips, and Lindsay Salvo
MajorsJan 08, 2026
Diamond Council of America Names New Board Directors

The nonprofit’s new president and CEO, Annie Doresca, also began her role this month.

Headshot of National Jewler columnist Peter Smith
ColumnistsJan 07, 2026
Peter Smith: Physical Retail—The Beginning or the End?

As the shopping mall model evolves and online retail grows, Smith shares his predictions for the future of physical stores.

Pinar Hakim Rainbow Seahorse Pendant, Nue Fine Jewelry Irene Charm, Susannah King Venus Ring
Events & AwardsJan 07, 2026
Melee Adds 13 New Designers to NYC Show

The trade show is slated for Jan. 31-Feb. 2 at The Lighthouse in New York City's Chelsea neighborhood.

×

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