GENEVA, SWITZERLAND - MAY 7: 1950s Colombian Emerald and Diamond Necklace fringed with large pear-shaped emeralds (Est. 1 2 million USD) is displayed as Sotheby's unveiled this morning highlights from its seasonal Geneva Important Watches and High Jewelry Sales, taking place live at the city's Mandarin Oriental Hotel on Sunday, 10 May from 11am CEST and Tuesday, 12 May from 2pm CEST. Both auctions will also be accessible online worldwide. Among the standout pieces is the jewellery sale's top lot: an exceptional six-carat Fancy Vivid Blue Diamond estimated at 912 million USD. The internally flawless stone comes from South Africa's Cullinan mine, source of several record-breaking blue diamonds. Also featured is a necklace, earring and bracelet set designed by Rihanna in collaboration with Chopard, first unveiled at the 2017 Cannes Film Festival and now appearing publicly and at auction for the first time. The necklace alone carries an estimate of 260,000380,000 USD. Additional highlights include a pair of perfectly matched unmounted 18.38-carat white diamonds sourced by De Beers (2.83.5 million USD), a likely unique 1928 ruby and diamond necklace by Lacloche Frères (200,000350,000 USD), and a 1950s Colombian emerald and diamond necklace estimated at 12 million USD. Leading the Important Watches Sale is an extremely rare 1916 A. Lange & Söhne Grand Complication Pink Gold Clock Watch estimated at 880,0001.5 million USD. Also featured is a rare 1969 Rolex Daytona "Paul Newman John Player Special" in 14-carat yellow gold (570,0001.1 million USD). The sale will additionally present pieces from the Shapes of Cartier Collection, the most comprehensive Cartier watch collection ever assembled, following record-breaking results in Hong Kong last month, including a world-record sale for a Cartier Crash on May 7, 2026 in Geneva, Switzerland. (Photo by Robert Hradil/Getty Images for Sotheby's)