An extremely rare diamond called The Eternal Pink is expected to fetch more than $35-million at a Sotheby’s auction, potentially breaking records as the most expensive price per carat ever to come to market.

The 10.57 ct diamond will go on show in Hong Kong next week and later will be exhibited in Dubai, Singapore, Shanghai, Taiwan and Geneva. It will be up for sale on June 8 in New York as the showpiece lot in a Sotheby’s jewels auction.

The cushion-cut diamond, which is mounted on a ring, has been described by experts as “glowing” and has the highest ranking possible for the quality of color, defined as “fancy vivid.” it has the top score for clarity, known as “internally flawless,” meaning that no blemishes are visible under 10x magnification. It’s among the most chemically pure of all diamonds, which contributes to its transparency.

The 2.1 g gem is comparable to “ultimate masterpieces of art”, according to Sotheby’s, which said it’s more unique than a Rene Magritte or Andy Warhol painting. “It is difficult to overstate its rarity and beauty,” said Wenhao Yu, chairperson of jewellery and watches at Sotheby’s Asia.

The Eternal Pink was mined by De Beers at the Damtshaa mine in Botswana. It took six months for artisans at Diacore in New York to fashion it.

The estimated price per carat for The Eternal Pink is $3.3-million, giving it a chance to challenge the record set by The Williamson Pink Star, which was sold at Sotheby’s Hong Kong in 2022 for $5.2-million per carat. That gem was bought by a private collector based in the US for $57.7-million.

Three pink diamonds feature in the top five diamonds by value ever sold at auction. They have become rarer since the closure of the Argyle mine in Australia, which was the largest supplier of the stones. Less than 3% of all the diamonds submitted to the Gemological Institute of America are colored and pink is the rarest of those.

Part of the appeal is the mystery because the pink hue isn’t fully understood by experts. It’s thought the shade comes from the stone’s formation process deep within the earth whereas other diamonds owe their color to precise trace elements such as nitrogen for yellow and boron for blue.