The Walska Briolette Diamond brooch, a renowned masterpiece of design, is another strong consignment to Sotheby's Magnificent Jewels sale in Geneva on November 13.

The diamond was formerly in the collection of Gann Walska, before being transformed into a brooch

The brooch, made by Van Cleef & Arpels in 1971, showcases the Walska Briolette Diamond, a fancy vivid yellow diamond weighing in a 96.62 carats. Taking its name from opera singer Ganna Walska, a jewellery connoisseur to whom it once belonged, it is expected at make $8m.

The diamond was originally purchased  by Van Cleef & Arpels at Sotheby's auction of the Jewels of Madame Ganna Walska. The brooch was commissioned a year later by an important American collection, with the jeweller giving the diamond a suitably lavish setting of yellow gold with yellow and white diamonds, emeralds and a cabochon sapphire.

The diamond can be detached and worn as a pendant, while the bird's wings can be used as earrings and the tail transformed into a stand-alone brooch.

"The 'Walska Briolette Diamond' Brooch is the perfect demonstration of how a great jeweller can emphasize the beauty of a spectacular stone by transforming it into a unique piece," commented Sotheby's David Bennet, chairman of jewellery in Europe and the Middle East.

"This historic diamond, which is of an extraordinary size for an antique-cut briolette, comes back on the market after 42 years, in a fabulous bespoke piece of jewellery."

Also starring in Geneva will be the Pink Star diamond, which is the most valuable diamond ever offered at auction at $60m.

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