After eight years, Gilbertson is leaving his post at the mining company, which is currently facing a slew of operational challenges.
The Iron Lady’s emerald necklace to hit auction block
The Chaumet Art Deco emerald and diamond necklace could garner as much as $274,000 when it goes up for sale next month as part of Christie’s auction of property from the late Margaret Thatcher.
London--Interested parties will have the opportunity to own a part of history when Christie’s puts a number of items belonging to former British Prime Minister Margaret Thatcher up for sale next month.
In December, the auction house will hold the “Mrs. Thatcher: Property from the Collection of the Right Honourable The Baroness Thatcher of Kesteven, LG, OM, FRS” sale of items related to her time in office.
It will comprise 150 lots sold in a sale at the Christie’s headquarters in London, as well as an online-only sale open running from Dec. 3 to 16 and featuring 200 additional lots.
Thatcher, who died in April 2013, served as the Prime Minister of the United Kingdom between 1979 and 1990.
The item expected to lead the sale is a circa 1930 Art Deco emerald and diamond necklace by Chaumet, which is estimated to garner between $182,600 and $274,000.
The auction house also will offer a circa 1800 George III diamond flower brooch pave-set throughout with old cushion, pear and circular-cut diamonds that could sell in the range of $12,100 and $15,200. Thatcher often was photographed wearing this brooch both in Britain and abroad and is, in fact, wearing the brooch in her official portrait hanging in the Prime Minister’s office in London.
Thatcher also was often seen wearing a strand of pearls. This sale will include a two-row cultured pearl necklace composed of 66 and 69 cultured pearls, which is predicted to sell for up to $2,300.
In addition to jewelry, the sale also will feature personal items like Thatcher’s midnight blue velvet wedding dress, her red leather Prime Ministerial Dispatch Box, and a 20th century Kaiser bisque figure of an American bald eagle presented to Thatcher by U.S. President Ronald Reagan.
Other items included are speech notes, an array of her attire, and 18th, 19th, and 20th century English porcelain, glass, gold boxes and silver.
The Latest

The new location is set to open this winter, featuring the retailer’s first rotating jewelry designer residency.

The pop artist appears in the latest campaign for the “Laurence Graff Signature” collection.

Colored gemstones, artisan finishes, mixed metals, and meaningful details are shaping demand in bridal jewelry.

One-of-a-kind pearls take the shape of ice cream cones, frogs, submarines, and other imaginative charms.


Charlotte Rose said her election is “a sign that this is an industry capable of change.”

Sponsored by Rio Grande Jewelry Supply

DCA is preparing the next generation of professionals by supporting workforce development, leadership growth, and career advancement.

The American jewelry house, founded by Latvian immigrants, has been creating American flag brooches since 1917.

The artwork celebrates the Atlanta jeweler’s legacy and symbolizes its commitment to supporting local artists and its community.

Its team can evaluate jewelry and watches, as well as luxury handbags, artwork, and collectibles.

Falling oil prices were a factor in the slight month-over-month improvement.

The new offering comprises more than 120 bridal and engagement ring styles with natural and lab-grown diamonds.

The clock is part of the celebration for the soon-to-open Rolex headquarters on New York City’s Fifth Avenue.

The public relations professional is remembered for her benevolent generosity and unwavering commitment to those around her.

The new watch commemorates Pokémon’s 30th anniversary.

The luxury retailer is now called Exemplar Luxury Group.

The “Lady” collection is a new take on old beauty standards with gemstone-adorned hair pins and combs, a compact mirror necklace, and more.

The new line is included in the e-tailer’s curation of jewelry celebrating America’s 250th anniversary.

All active members who earned their credential or designation before Dec. 1, 2025, are required to recertify.

The new jewelry collection uses a colorful palette of onyx, malachite, tiger’s eye, mother-of-pearl, lapis, turquoise, and coral.

Lee Michaels Fine Jewelry is celebrating 30 years in the Ridgeland, Mississippi community.

Sean Milliner has joined the company.

Classes will begin in August at GIA’s new Canary Wharf location.

The rainbow version of the ring, our Piece of the Week, features angel-cut, octahedral lab-grown sapphires designed to be worn as armor.

The new initiative donates a portion of the proceeds from select charms to charitable causes.

The Brooklyn-based jeweler created a limited-edition version of its “Aura” eternity band, set with gemstones in the team’s colors.





















