Editors

10 Things I Learned at the AGA’s Tucson Conference

EditorsFeb 27, 2019

10 Things I Learned at the AGA’s Tucson Conference

They include updates on the state of the North American natural pearl market, Ethiopian emeralds and tourmaline production.

20190227_Shakiso-emerald.jpg
They include updates on the state of the North American natural pearl market, Ethiopian emeralds and tourmaline production.

Tucson is not only full of amazing gems but also more knowledge and education than the gem crowd could ever ask for.

Sitting in on these sessions is one of my favorite parts of the trip, since my job requires me to always keep learning, and this year I was thrilled to add the Accredited Gemologists Association’s conference to my schedule.

I learned so much more than could be incorporated into a single blog, but here are just a few of the things I thought you’d all enjoy knowing too, ranging from gemological knowledge to market updates.

1. Locals have full control of the Halo-Shakiso emerald mine in Ethiopia.

The mining site, located about 37 miles from the town of Shakiso, is currently owned by the Bu’a Obsa Cooperative, a group of locals who initially banded together for gold and tantalum mining. It now has hundreds of shareholders from the local community that benefit from the emerald mining.

According to Jeffery Bergman of Primagem in Thailand, only the local tribespeople are allowed access to the mining site at Halo; they dig, extract, sort and grade the material.

2. There’s a variety of material that comes from Halo-Shakiso, including some “really exceptional” gem-quality rough.

According to Bergman, the bases of the emerald crystals are typically heavily included, so the excitement about the material surrounds the top part, where you can find some “really exceptional” gem-quality material.

Bergman also noted during his presentation that about 20 percent of production from the Halo mine doesn’t need any clarity enhancements.

3. Ethiopian emeralds share similarities with other emeralds with schist-based origins so they look like the material from Brazil and Zambia.

This means, Bergman said, that trace element analysis must be done to ascertain a stone’s origin, rather than relying on just inclusions; the GIA said in a 2017 Gems & Gemology article that it was able to separate the material from other sources by comparing trace alkali metals and some transition metals.

RELATED CONTENT: 5 Things to Know About … Ethiopian Emeralds
4. The group in control of the Halo-Shakiso emeralds has been working to build it as a brand, mimicking the work of other areas that have done it successfully, such as Muzo.

As part of a project in which Bergman participated but is no longer associated, the Bu’a Obsa association created a logo, slogan, website, obtained photography, established a presence
on social media, created ads and has increased its presence at trade shows.

It remains to be seen how the group will be able to establish their emeralds on the world market, especially given the Ethiopian government’s increasing control over the material.

5. The natural pearl market in the United States is actually a by-product of the button industry, Gina Latendresse of the American Pearl Company said.

By the late 1800s, the freshwater pearl button industry in the U.S. was flourishing, thanks to the number of mussels available in the country’s waters as well as the availability of cheap labor.

Decades later, this would give way to a new market created around cultured pearls in Japan, and, specifically, their need for the nuclei from North American natural pearls.

“All cultured pearls around the world, if they’re using a mother-of-pearl bead, they have a little bit of Tennessee or Mississippi River tributary mollusk inside of them,” she said.

6. As is the case with all pearls, North American natural pearls are rare.

According to Latendresse, only one in 10,000 mussel shells in the U.S. turns up a pearl. Of those, only 5 percent are symmetrical and only 1 percent are more or less round.

7. Natural pearls in North America come in a variety of beautiful, baroque shapes.

The wing shape is arguably the most recognizable, Latendresse said, and lends itself well to jewelry design; they have been used in creations by big brands, such as the Chrysanthemum brooch from Tiffany & Co.

There also are rosebuds, turtlebacks (baroque ovals), drop shapes, bodices, button shapes, snail formations and many others.

North American natural pearls also come in several colors, including white, pink, purple and lavender, as well as the greens and blues from abalone shells on the West Coast, and the pinks and oranges with a flame pattern that’s seen in the conch pearl.
RELATED CONTENT: 5 Things to Know About … Conch Pearls
8. Tourmaline has a number of gemological characteristics that make it interesting to the trade.

For one, it can have a very pronounced pleochroism, said Claudio Milisenda, managing director of DSEF German Gem Lab in Idar-Oberstein. This is of great importance to cutters so it can be oriented a certain way.

It also has the capability to polarize light going through the stone, which is why slices of tourmaline cut parallel to the prism were used as a polariscope in ancient times, Milisenda said.

Additionally, tourmaline often shows distinct color zoning, which makes crosscuts of the crystals very popular with collectors.

9. The blue component in blue-green Namibian tourmaline can be removed through heating to make it greener.

Milisenda said darker stones also can be lightened through heat treatment.

This is important to note because both can be done by heating the stones at a temperature of about 650 degrees centigrade, so if it’s a relatively clean stone the inclusion pattern “hardly will change,” he said.

This means there’s no way to detect if this kind of tourmaline has been heat-treated or not, unless it is heated at a temperature above 700 degrees centigrade and checked using a refractometer.

Milisenda also said tourmaline’s color in general can be improved by irradiation. He noted that it’s common for pink tourmaline to be irradiated though it can’t be detected, presenting a dilemma to gemstone dealers.

“How can we disclose that when we are selling pink or red rubellite to a client?” he asked.

10. Here’s a quick production update on Paraiba tourmaline (meaning copper-bearing tourmaline in his case, as per the Laboratory Manual Harmonisation Committee).

Milisenda said supply in Brazil is very low—the Mulungu mine is working through the tailings, and there’s no production at Batalha currently.

He added that Nigeria never had continuous production, and Mozambique is producing an increasing amount of cabochon-quality material.
Brecken Branstratoris the senior editor, gemstones at National Jeweler, covering sourcing, pricing and other developments in the colored stone sector.

The Latest

Elton John’s leopard print Rolex Daytona watch
AuctionsFeb 22, 2024
Elton John’s Leopard-Print Rolex Roars at Auction

Two Cartier watches also topped their estimates at Christie’s “The Collection of Sir Elton John: Goodbye Peachtree Road” evening sale.

Buccellati header
TrendsFeb 22, 2024
Buccellati to Open ‘Prince of Goldsmiths’ Exhibition

Set to be held in Venice, it’s a look through the maison’s history.

813-carat “Constellation” diamond in rough form
SourcingFeb 22, 2024
Lucara, HB Group Partnership Revived

It is another 10-year sales agreement in which all the larger rough recovered from the Karowe mine will go to HB Group for manufacturing.

GIA id100
Brought to you by
Full Disclosure at Your Fingertips

Distinguishing natural diamonds from laboratory-grown stones – now more available than ever – has been difficult for jewelers. Until now.

Sebastian Clarke and Katherine van Dell of Heritage Auctions
AuctionsFeb 22, 2024
Heritage Auctions Adds 2 New Hires to West Palm Beach Office

Sebastian Clarke and Katherine van Dell, frequent appraisers on “Antiques Roadshow,” will join the new office.

Weekly QuizFeb 22, 2024
This Week’s Quiz
Test your jewelry news knowledge with this short test.
Take the Quiz
National Jeweler columnist Sherry Smith
ColumnistsFeb 21, 2024
On Data: January Was a ‘Mixed Bag’ for Independent Jewelers

Sherry Smith dishes on the month’s highs and lows and the two categories consumers were loving ahead of Valentine’s Day.

Stock image of diamonds
GradingFeb 21, 2024
GIA’s Same-Day Service Now Available Everywhere

The new service, introduced to stem fraud related to lab-grown diamonds, will be offered at no cost for the time being.

flashforge pic.png
Brought to you by
WaxJet: Revolution in Jewelry Manufacturing

The WaxJet 400, recognized as the world's fastest wax printer, is bringing in a new era of precision and efficiency to industry.

Jam + Rico Claire’s jewelry
CollectionsFeb 21, 2024
Jam + Rico Debuts Second Claire’s Collection

Founder Lisette Scott was inspired by the intricacy, colors, and symbolism of African art and architecture.

Rapaport logo
SourcingFeb 21, 2024
Rapaport to Hold Another Natural Pearl Auction

Viewings start this week in New York and bidding will close on March 8.

National Jeweler columnist Peter Smith
ColumnistsFeb 20, 2024
Squirrel Spotting: Life After Rolex

Peter Smith shares advice from independent jewelers who used losing this cornerstone brand as a catalyst for reinvention.

Neile Adams McQueen and Steve McQueen
AuctionsFeb 20, 2024
Jewels from Neile Adams McQueen Shine at Bonhams

All 13 lots belonging to the actress and first wife of Steve McQueen sold at the recent “California Jewels” sale.

Stuller bench jeweler
Events & AwardsFeb 20, 2024
Stuller to Host Bench Jeweler Workshop in March

Registration is also open for its “Battle of the Benches” challenge.

Mary Ball Gorman of Henry B. Ball Jewelers
IndependentsFeb 16, 2024
Mary Ball Gorman of Henry B. Ball Jewelers Dies at 99

Gorman was an industry trailblazer, serving as the first female treasurer of Jewelers of America.

Jade Ruzzo gold and diamond Tennessee Torque necklace
CollectionsFeb 16, 2024
Piece of the Week: Jade Ruzzo’s Tribute to Tennessee

The movement of the 18-karat gold and diamond “Tennessee Torque” necklace is subtle.

Jared Goff and Claudia Cividino
MajorsFeb 15, 2024
Detroit Lions’ QB Jared Goff Going to Jared

Goff, whose fans hold up “He Went to Jared” signs at games, has signed a partnership with the retailer.

De Beers Venetia diamond mine
SourcingFeb 15, 2024
De Beers’ Production Down 8% in 2023

The company recovered 31.9 million carats of diamonds in 2023, compared with 34.6 million in 2022.

Gina D’Onofrio Heritage Auctions
AuctionsFeb 15, 2024
Heritage Auctions Names New Co-Director of Fine Jewelry

Industry veteran Gina D’Onofrio has rejoined the auction house.

Indian Diamond and Colorstone Association (IDCA) awards
Events & AwardsFeb 15, 2024
IDCA Hands Out Awards in Tucson

The association also celebrated its 40th anniversary.

A selection of engagement rings
TrendsFeb 14, 2024
5 Engagement Ring Trends for 2024

From three-stone rings to fancy shapes, experts weigh in on what consumers could be looking for this year.

Boucheron Power of Couture
CollectionsFeb 14, 2024
Boucheron’s New High Jewelry Collection Pays Homage to Ceremony, History

“Power of Couture” recalls Frédéric Boucheron’s love of fabric using diamonds and rock crystal.

Rough diamonds from Gahcho Kue diamond mine
SourcingFeb 14, 2024
De Beers’ Rough Diamond Sales Improve Slightly

The diamond miner and marketer said “solid” holiday sales in the U.S. helped stabilize the industry.

Jonker I Diamonds
SourcingFeb 14, 2024
‘100 Carats’ Exhibition Opens at LA Museum

A new display at the Natural History Museum of Los Angeles County features dozens of gemstones each weighing 100 carats or more.

Grand Seiko New York City flagship
WatchesFeb 14, 2024
See Inside Grand Seiko’s New NYC Flagship

Located on Madison Avenue, the store is its largest in the world.

GIA logo
GradingFeb 14, 2024
GIA Offering Discounts on Jade Reports

The 20 percent off promotion will run through March 31.

KIL Promotions NYC Spring Jewelry and Object Show
Events & AwardsFeb 14, 2024
KIL NYC Show Returns for Spring Edition

Its second trade event will feature vintage pieces and contemporary collections.

Lydia Courteille Lips ring
TrendsFeb 13, 2024
Amanda’s Style File: Symbols of Love

When it comes to Valentine’s Day jewels, the fun doesn’t stop at hearts.

×

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