(IDEX Online) - The world's largest vivid purple-pink diamond to be offered at auction could fetch $38m, says Sotheby's. The ultra-rare, IF-clarity, Type IIa 14.83-carat gem was mined and cut by Alrosa and is the largest pink rough diamond ever produced in Russia.It has been named after a celebrated Russian ballet, The Spirit of the Rose and will be offered at the Magnificent Jewels and Noble Jewels' auction in Geneva on 11 November. It is being shown in Hong Kong, Singapore and Taipei.Demand for pink diamonds is currently at fever pitch, with just weeks to go before the closure of Australia's iconic Argyle mine - supplier of 90 per cent of the world's pink diamonds since 1984.Sotheby's say the estimate is $23m to $38m.Alrosa said: "It took a whole year for Russian cutting masters to turn a unique diamond, discovered in Yakutia, into a genuine treasure with fancy vivid purple-pink color, internally flawless clarity, excellent polish and very good symmetry characteristics."The oval shape ensured that the diamond would be of the maximum possible size, and the dozens of facets emphasize its gentle, rose-petal color."It was cut from a 27.85-carat clear pink rough diamond unearthed on 9 October 2017 from the Ebelyakh deposit in the Republic of Sakha (Yakutia) in northeast Russia.Gary Schuler, worldwide chairman of Sotheby's jewellery division said: "The occurrence of pink diamonds in nature is extremely rare in any size. Only one per cent of all pink diamonds are larger than 10-carats and only four per cent of all pink diamonds are graded 'Fancy Vivid' and display a rich, vivid color."Having the opportunity to offer a large polished pink diamond of over 10-carats and with the richness of color and purity of The Spirit of the Rose is therefore truly exceptional."