A stunning diamond brooch, estimated to fetch between 5.6 million and 6.5 million Swiss Francs ($6.1 million – $7.1 million), will be auctioned by Sotheby’s in Geneva on May 14.
The centerpiece is the Fancy Vivid Yellow Cartier diamond brooch, known as the Allnatt diamond. Weighing over 100 carats, this gem is expected to draw significant interest.
Catharine Becket, head of Magnificent Jewels sales at Sotheby’s, described the piece: “What I’m holding here is the magnificent Allnatt diamond, mounted by Cartier in 1952. The first known owner was Major Alfred Ernest Allnatt, a British sportsman, Old Master paintings collector, and philanthropist. He brought the stone to Cartier in 1952, where it was set in this beautiful flower-inspired mount.”
Believed to have been mined in South Africa over a century ago, the Allnatt diamond has been featured in international exhibitions, including at the Smithsonian Museum in Washington, DC. This marks its first sale in nearly 30 years.
“The stone weighs 101.29 carats, is a fancy vivid yellow, the top color grade, and has VS2 clarity,” Becket noted. “What’s particularly notable is its high crown, showcasing an older cutting style.”
Another highlight of the Sotheby’s Magnificent Jewels and Noble Jewels Sale is an Internally Flawless, E color diamond weighing 37.61 carats, expected to sell for 1,460,000 CHF – 2,370,000 CHF ($1.6 million – $2.6 million).
The auction will feature approximately 120 lots, many with six or seven-figure estimates. It will be held at the Mandarin Oriental hotel in Geneva on May 14.
