During its Q3 call, CEO Efraim Grinberg discussed the deal to lower tariffs on Swiss-made watches, watch market trends, and more.
In NYC, An Auction That’s Bound to Delight Rock Hounds
In 2017, Guernsey’s will offer a collection of Muzo Colombian emeralds and star rubies in two separate events.

On April 25, the company will offer the Marcial de Gomar Collection, comprised of more than 20 loose emeralds--both cut and rough--plus 13 pieces of emerald jewelry.
The emeralds in this collection come from the personal collection of Manuel Marcial de Gomar, the founder of Emeralds International LLC, who spent more than five decades in the gemstone business. This includes years working in the Muzo mines in Colombia, known to supply some of the best emeralds in the world.
His knowledge of the South American emeralds also has led him to become an author, lecturer and consultant. His family still is involved in the rare emerald business.
A notable lot in the collection is the 887-carat La Gloria, the largest Muzo rough emerald in North America, according to the auction house.
There also is the Marcial de Gomar star emerald. At 25.86 carats it is the largest of only 11 star emeralds known to exist, according to the Gemological Institute of America. It also is rare in that it is a double-sided star emerald, meaning it exhibits the phenomenon on both sides.
Marcial de Gomar knew famed American treasure hunter Mel Fisher, who brought him in for his expertise after he discovered the wreck of the Spanish ship Nuestra Señora de Atocha off the coast of Florida in 1985. Muzo emeralds were part of the haul that surfaced from that shipwreck.
A few gold coins, such as the one pictured here, from the wreck of the Nuestra Señora de Atocha in the Florida Keys will be included in the April auction.
A few of the stones, as well as some rare gold coins from the discovery, eventually came to be in Marcial de Gomar’s collection and are included in the April auction.
Then in June, Guernsey’s will auction off the Mountain Star Ruby Collection. This is comprised of four “extraordinary” star rubies weighing 342 carats total, which will be sold together as one lot.
“It was suggested to us that part of the extraordinary nature of them is where they were found and their individual brilliance, but also the fact that they are four matching stones and it would be crazy, almost criminal, to destroy the collection and the set,” Guernsey’s President Arlan Ettinger told National Jeweler.
Jarvis Wayne Messer found the stones in western North Carolina in 1990.
Although Messer made his living as a fishing guide in the area, he was a self-described rock hound who made a number of interesting discoveries that ended up in museums across the country.
When he first found the star rubies, he was lacking the necessary funds to prove the importance of his discovery, so he got a friend to cut the stones into their cabochon shapes to reveal the stars.
He then enlisted friends to put forward money to have the stones looked at it, giving them a share in the stones and the results from the findings in exchange.
After being examined by a number of gemological labs, including the GIA, the largest of the four, the 139.43-carat Appalachian Star Ruby, went on display at the Natural History Museum in London, where it drew more than 150,000 visitors in just a few weeks, Ettinger said.
Shortly after the exhibit, Messer died and the collection went to his family, with whom it has remained since. A friend of Messer’s, who also was one of the original “investors” in the find, is the one who reached out to the auction house.
Guernsey’s did not provide any pre-sale estimates on the gemstones.
Ettinger said that the Mountain Star Ruby Collection will be offered without a minimum reserve, while about half of the Manuel Marcial de Gomar Collection will be offered without a reserve price.
“These are wonderful and important stones,” he said. “The world will determine what they’re worth.”
Ettinger also noted that a number of experts who have examined the Appalachian Star Ruby throughout its history have compared it to the 138-carat Rosser Reeves Star Ruby, which is one carat smaller and actually has only a five-sided star as one line is broken.
The Rosser Reeves was appraised at $25 million in the early 1980s and about 20 years later at $40 million, according to Guernsey’s.
“By comparing Rosser Reeves to the Appalachian Star, the Appalachian Star, by every account, seems to come out ahead,” he said. “That’s not condemning Rosser Reeves at all; it’s simply saying that may be great, but so is this one. In fact, this one may even be slightly greater.”
Sales of the two family-owned collections will be held live at the Americas Society on Park Avenue in Manhattan, with online bidding held at LiveAuctioneers.com.
Though Guernsey’s has only sold jewelry only once before--a diamond and South Sea pearl necklace and matching earrings worn by the late Princess Diana--the auction house is not unused to holding auctions of rare and valuable items.
Notable past auctions have included a collection covering all eras of the life of John F. Kennedy, the contents of the S.S. United States and, most recently, the complete archives of Rosa Parks.
But within the past 10 days, the auction house has been offered another opportunity to auction off an exceptional mineral piece.
“If this is a new direction for Guernsey’s, I’m thinking of it like a surf board and I’m riding the waves,” Ettinger said.
Editor’s Note: This story was updated on February 14, 2017, to reflect a change in the dates of the auctions made by Guernsey’s.
The Latest

Rosior’s high jewelry cocktail ring with orange sapphires and green diamonds is the perfect Thanksgiving accessory.

The “Embrace Your True Colors” campaign features jewels with a vibrant color palette and poetry by Grammy-nominated artist Aja Monet.

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

Luxury veteran Alejandro Cuellar has stepped into the role at the Italian fine jewelry brand.


The company gave awards to four students at the Namibia University of Science & Technology, including one who is a Grandview Klein employee.

She is remembered as an artist who loved her craft and was devoted to her faith, her friends, and her family.

Roseco’s 704-page catalog showcases new lab-grown diamonds, findings, tools & more—available in print or interactive digital editions.

It joins the company’s other manufacturing facilities globally, including in India, Botswana, and Namibia.

The polka dot pattern transcends time and has re-emerged as a trend in jewelry through round-shaped gemstones.

Vanessa Hickman, 49, allegedly sold a diamond bracelet that was mistakenly sent to her home.

GIA’s former president and CEO was presented with the Richard T. Liddicoat Award for Distinguished Achievement.

Social media experts spoke about protecting brand reputation through behaving mindfully online.

In 2026, the three will come together as “House of Brands,” with Gallet sold in Breitling stores and Universal Genève sold separately.

The second drop, which includes more Elphaba-inspired pieces from additional designers, will continue to benefit nonprofit Dreams of Hope.

Second-generation jeweler Sean Dunn has taken on the role.

Amber Pepper’s main focus will be on digital innovation and engaging younger consumers.

Called “Origin by De Beers Group,” the loose, polished diamonds are being sold in a total of 30 stores in the United States and Canada.

The lariat necklace features a 4.88-carat oval-cut Zambian emerald in 18-karat yellow gold.

Rau is a fourth-generation art and antique dealer from M.S. Rau gallery whose first jewelry collection merges artifacts with modern design.

Former De Beers sustainability leader Purvi Shah will take over the role in February 2026.

La Joux-Perret is based in La Chaux-de-Fonds, Switzerland, and makes solar quartz as well as mechanical watch movements.

She previously taught at Gem-A and is the founder of The Gem Academy.

The British actress and her daughter modeled pieces from the brand’s new “Palette” capsule for its “Once Upon a Time” holiday campaign.

Plus, the tech giant shares the steps retailers should take if they believe they’re a victim of a review extortion scam.

Danny and Gaby Shaftel are now Shaftel Diamonds’ CEO and chief operating officer, respectively.

The jewelry manufacturer’s seasonal offering features its new “Melodie” bangles, as well as mini stud earrings and layering pieces.






















