This March, luxury diamond house De Beers joined forces with Sotheby’s to unveil a breathtaking 28.88-carat diamond, set to go under the hammer as part of Sotheby’s Luxury Sales in Hong Kong in April.
The unveiling was announced for the very first time at an exclusive event held by De Beers at the iconic Maison Assouline in London to celebrate the newly launched book, A Diamond Is Forever: The Making of a Cultural Icon 1926– 2026.
In attendance at the event were Poppy Delevingne, Nathalie Emmanuel, Archie Madekwe, and former H! Fashion cover star Ruby Sear, to name a few.
© Dave Benett/Getty Images for De
© Dave Benett/Getty Images for DeThe Jwaneng 28.88 was discovered in Botswana’s famed Jwaneng mine. The extraordinary 28.88-carat diamond is as rare as it is remarkable - graded D in colour and internally flawless, the stone began its journey as a 114.83-carat rough before being expertly transformed by De Beers’ master craftsmen over several months into a perfectly cut round brilliant.
Classified as a Type IIa diamond - the most chemically pure and exceptionally rare category, accounting for less than two per cent of all natural diamonds - its clarity and brilliance place it in a league of its own.
Al Cook, Chief Executive Officer of De Beers Group, said: “Humanity’s love of diamonds goes back thousands of years. Their beauty, strength and rarity make them the most treasured of Earth’s creations. Over the past century, De Beers has shared the love of diamonds across the world. A Diamond is Forever, The Making of a Cultural Icon and this exhibition chart 100 years of storytelling, creativity, and artistry — honouring how natural diamonds carry stories across billions of years, from deep within the Earth to the hands of those who treasure them. I am proud to partner with both Assouline and Sotheby’s to continue sharing the diamond dream.”
© Dave Benett
© De BeersFormed billions of years ago deep within the Earth’s mantle, the diamond was brought to the surface by ancient volcanic forces beneath today’s Kalahari Desert.
“The Jwaneng 28.88 is a perfect emblem of De Beers’ unmatched legacy in diamonds," said Quig Bruning, Sotheby’s Head of Jewels Americas and EMEA. "It’s at once a vanishingly rare feat of nature, combined with a masterclass in diamond cutting and polishing. Natural diamonds truly are forever, and I cannot think of a better stone to symbolise this special collaboration.”
The diamond will be auctioned at Sotheby’s Live High Jewelry Sale in Hong Kong on 23 April 2026, where it will take centre stage among a curated edit of exceptional stones from the same mine. Together, they showcase the very best of natural diamond rarity and expert craftsmanship, presented on a global stage by one of the world’s leading auction houses.
