Auctioneers Sotheby’s said that a rare pink diamond valued at up to $38 million (€28 million) would go on sale in Geneva next month, dubbing it one of the “world’s most desirable stones.”

The 24.78 carat Fancy Intense Pink Diamond mounted on a ring comes from a private collection, the auction house said.

The gemstone, rated among a type that accounts for just two percent of diamonds, was last seen on the market about 60 years ago when it was sold by legendary US jeweller Harry Winston.

“During my 35-year career at Sotheby’s I have had the opportunity to examine many magnificent and rare gemstones and, put simply, this stone is one of the most desirable diamonds I have ever seen,” said David Bennett, chairman for Europe and the Middle East at Sotheby’s international jewellery department.

“What makes it so immensely rare is the combination of its exceptional colour and purity with the classic emerald-cut – a style of cutting normally associated with white diamonds,” he added.

Sotheby’s gave a pre-sale estimate of $27 to $38 million for the fancy pink diamond, which will go under the hammer on November 16.

Blue, pink and green coloured diamonds are currently the most sought-after gemstones in auctions, according to the auction house.

Several elite auctioneers including rivals Christie’s hold glittering jewellery sales every year in the western Swiss city’s luxury hotels during one week in spring and autumn.