A sparkling assortment of rare fancy colour diamonds, coloured gemstones and heritage jewellery will headline upcoming auctions in Geneva and New York.

Christie’s Geneva will present more than 700 one-of-a-kind jewellery pieces from late billionaire Heidi Horten’s collection, which could collectively fetch US$150 million. This is the largest and most valuable private jewellery collection ever to come to auction and could potentially beat previous record sales at Christie’s for The Elizabeth Taylor Collection in 2011 and the Maharajas & Mughal Magnificence auction in 2019.

Proceeds from the sale will be donated to The Heidi Horten Foundation, which supports the museum of modern and contemporary art founded by Horten in Vienna, Austria as well as medical research and other philanthropic activities aided by Horten.

Highlights of the sale include the 90-carat Briolette of India diamond necklace by Harry Winston; a three-strand natural pearl necklace also by Harry Winston; and the 25-carat Sunrise ruby and diamond ring by Cartier with a pre-sale estimate of US$15 million to US$20 million, among other offerings. 

Rahul Kadakia, Christie’s international head of Jewellery, remarked, “The World of Heidi Horten is the collection of a lifetime. From Bulgari to Van Cleef & Arpels, from a small personal memory piece to the Briolette of India, this is a collector’s dream.” 

Christie’s will present 400 of the 700 jewels across two live auctions, beginning May 10 and May 12, 2023, as well as online auctions in May and November.

Meanwhile, Sotheby’s is offering the 10.57-carat cushion-cut internally flawless fancy vivid purplish pink diamond named The Eternal Pink. It is the most vivid pink diamond ever to come to market, according to Sotheby’s. The diamond is expected to fetch more than US$35 million.

“Fancy vivid is the highest possible for a fancy colour diamond. The modifying colour of purple often results in the most charming and vibrant feminine hue that is the dream of many,” the auction house said. “Polished as a cushion-cut, this gemstone boasts an attractive combination of facets that enhances the pink to be ‘sweeter’ to one’s eyes.” The Eternal Pink will be offered as part of Sotheby’s Magnificent Jewels auction on June 8 at Sotheby’s New York.

Sotheby’s is also presenting the 55.22-carat Estrela de Fura (Star of Fura in Portuguese) Mozambique ruby at the New York auction. Described as the largest gem-quality ruby to ever appear at auction, it features a rich saturation of colour, untouched by heat treatment, highly crystalline appearance and incomparable size. It is estimated to fetch more than US$30 million – making it the most valuable and important ruby ever to come to market. The gem-quality rough ruby, weighing 101 carats, was unearthed by Fura Gems in 2022.

“Estrela de FURA is poised to make history as it sets to surpass The Sunrise Ruby, a 25.59-carat ruby of Burmese origin, which sold for US$30.3 million at Sotheby’s Geneva in 2015, and still holds the world auction record for a ruby,” the auction house said.