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

Bergman Jewelers family
IndependentsApr 01, 2025
Bergman Jewelers in Omaha Closing After 137 Years

The independent jeweler first opened its doors in 1888.

QVC Group Inc. logo
MajorsApr 01, 2025
QVC Group to Cut 900 Jobs in the U.S.

The layoffs come amid the TV shopping channel’s efforts to restructure and focus on live shopping through social media.

Coconut Grove Jewelry & Watch Show
Events & AwardsApr 01, 2025
U.S. Antique Shows Adds Fall Show in Florida

The debut event will take place in Miami’s Coconut Grove neighborhood this fall.

bench jeweler 1872x1052.png
Brought to you by
The Heart of the Industry: Giving Bench Jewelers the Recognition They Deserve

Bench jewelers spend years honing their skills, Jewelers of America’s Certification validates their talents.

The Jewelry Symposium (TJS)
Events & AwardsApr 01, 2025
TJS to Host Discussion on Jewelry Industry’s Labor Shortage

The roundtable will take place May 17 ahead of the trade show’s welcome dinner.

Weekly QuizMar 27, 2025
This Week’s Quiz
Test your jewelry news knowledge by answering these questions.
Take the Quiz
Peanuts x Monica Rich Kosann Collection Bracelets
CollectionsApr 01, 2025
Monica Rich Kosann Says ‘Good Grief’ in Peanuts Jewelry Collection

The “Peanuts x Monica Rich Kosann” collection features the comic strip’s classic vocabulary across 10 bracelet designs.

Graphic for What Do We Mean When We Say “Recycled” Gold webinar
Recorded WebinarsMar 31, 2025
Watch: What Do We Mean When We Say ‘Recycled’ Gold?

Three industry experts dive into the complexities of the material often marketed as an “ethical” alternative for metal in jewelry.

Facets-of-Fire-Difference-You-Can-See.jpg
Brought to you by
Natural Diamonds Should Mean More

Natural diamonds mean more than lab-grown, but when every cut is ideal, they all look the same. Customers want more—Facets of Fire delivers.

Mindi Mond Clarity Earrings
TrendsMar 31, 2025
Amanda’s Style File: Dripping in Diamonds

Diamonds are not only one of the most prominent gemstones, but the birthstone for those born in April.

Lashbrook ring
MajorsMar 31, 2025
Lashbrook Expands Into Luxury Golf Gifts With Acquisition

The Utah-based company known for making wedding bands has acquired Doubloon Golf.

Bulgari and LVMH Watches CEO Jean-Christophe Babin
WatchesMar 31, 2025
Bulgari CEO Jean-Christophe Babin Will Also Head LVMH Watches

The longtime luxury executive led one of LVMH’s watch brands, TAG Heuer, for 12 years before taking over Bulgari in 2013.

Surveillance footage of robbery
CrimeMar 28, 2025
2 Suspects Arrested in $1.7M Smash-and-Grab Robbery of NY Jewelry Store

Authorities said the robbers fled with jewelry and 70 Rolex watches, later taking pictures of themselves posing with big stacks of cash.

Nephrite and Jadeite by Heinrich Fischer, Richard W. Hughes
SourcingMar 28, 2025
19th-Century Jade Book Now Available in English

Lotus Gemology founder Richard W. Hughes has translated Heinrich Fischer’s 1880 book “Nephrit und Jadeit” from its original German.

LÖF The Valentine Ring
CollectionsMar 28, 2025
Piece of the Week: Löf’s ‘The Valentine’ Ring

The ring's design features contrasting lines influenced by work from architecture-inspired photographer Nikola Olic.

Eggs on a shelf
SurveysMar 27, 2025
Consumer Confidence Falls in March Amid ‘Gloomy’ Outlook

The Conference Board’s index fell as consumers continued to worry about the impact of tariffs, the labor market, and the price of eggs.

Richard Rainsford memorial ring
AuctionsMar 27, 2025
300-Year-Old Ring Linked to Witch Trial Judge Goes Unsold at Auction

However, two medieval jewels surpassed estimates at Noonans Mayfair’s recent jewelry auction in London.

Austin Butler
WatchesMar 27, 2025
Austin Butler Joins Breitling as Brand Ambassador

The Oscar-nominated actor debuted in the campaign for the new “Top Time B31” collection, which introduced Breitling’s Caliber B31.

ICA Congress Brazil 2025
SourcingMar 27, 2025
Susan Jacques, Gaetano Cavalieri to Headline 2025 ICA Congress

The Congress is scheduled to take place May 19-22 in Brasilia, Brazil.

Bailey’s Fine Jewelry storefront
IndependentsMar 26, 2025
Bailey’s Fine Jewelry Acquires Fellow NC Independent Jeweler

The family-owned retailer is the new owner of Morrison Smith Jewelers in Charlotte, North Carolina.

Bulova 150 Art Deco Miss America Watch, 150 Art Deco Pocket Watch
WatchesMar 26, 2025
Bulova Celebrates 150th Anniversary With Art Deco Watches

The “150 Art Deco” collection features a Miss America timepiece and a pocket watch from the brand’s Archive Series.

Alex Wellen
MajorsMar 26, 2025
QVC Group Appoints New President

Alex Wellen, formerly CEO and president of MotorTrend Group, has taken on the role.

Jewelers of America’s new logo
Events & AwardsMar 26, 2025
Jewelers of America Announces New Funding Initiative

The Impact Initiative is part of the nonprofit association’s new three-year strategic plan.

Christies regent kashmir sapphire and regal Burmese ruby
AuctionsMar 25, 2025
Christie’s To Auction 35-Carat Sapphire, 13-Carat Ruby

The ruby and the sapphire, which Christie’s calls a “once-in-a-generation masterpiece,” are part of the upcoming Hong Kong jewelry auction.

Diamond earrings held in gloved hand
CrimeMar 25, 2025
Tiffany & Co. Earrings Swallowed Following Grab-and-Run Theft Recovered

The two pairs of earrings, snatched from a Tiffany & Co. store in Orlando, Florida, are valued at a combined $769,500.

Emmanuel Raheb CEO of Smart Age Solutions
ColumnistsMar 25, 2025
The Smart Lab: Using Short-Form Videos to Sell More Jewelry

The time to start experimenting with video content is now, writes columnist Emmanuel Raheb.

Pomellato Nudo High Jewelry Campaign
CollectionsMar 24, 2025
Pomellato’s Latest ‘Nudo’ Collections Revamp its Classic Design

From striking high jewelry to miniature fine jewelry, the new chapter continues to highlight gemstones featuring its signature 57-facet cut.

Jamie Singleton, Bill Brace, Rebecca Wooters, Bill Luth
MajorsMar 24, 2025
4 Top Executives to Depart Signet Jewelers Amid Turnaround

The jewelry giant is reducing its senior leadership by 30 percent as part of its new turnaround strategy.

×

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