A rare, pear-shaped, vivid pink diamond will go under the hammer at auction in Geneva next month, where auctioneers expect the unusual gem to fetch £27 million.
The 'Unique Pink', described by Sotheby's as 'supremely rare and exceptional', weighs 15.38 carats.
David Bennett, worldwide chairman of Sotheby's international jewellery division, told Reuters: "The Gemological Institute of America, the highest body for grading diamonds, have given this stone their highest possible grading, which is vivid pink".
"It's the largest pear-shaped fancy vivid pink diamond ever to be offered at auction."
The discovery of gem-quality pink diamonds is rare, according to Sotheby's, which will auction this one as part of its "Magnificent Jewels and Noble Jewels" sale in Geneva on May 17.
"We're estimating between $28-38 million," Bennett said of pre-sale estimates during a preview of the diamond in London.
"There have been a couple ... of stones that have sold for around £1.4 million per carat or a little more historically so it seems to be perfectly correctly estimated... We will see."
Earlier this week, a 10.10 carat oval, internally flawless, fancy vivid blue diamond sold for £22.5 million at an auction held by Sotheby's in Hong Kong.
Other items to go up for sale in the same auction include 'The Emperor Ruby' a ruby and diamond ring estimated to sell for between £3.6 million and £5.75 million and a diamond brooch expected to sell for between £7.2 and £10.01 million.
You can find out more about the unique diamond and follow it's progress on the Sotheby's website here.