De Beers Group, in partnership with Sotheby’s, has unveiled a rare 28.88-carat diamond from Botswana’s Jwaneng mine, ahead of its auction debut at Sotheby’s High Jewellery sale in Hong Kong on 23 April 2026.

Named the “Jwaneng 28.88,” the stone is a round brilliant, D-colour, internally flawless diamond classified as Type IIa — a category representing fewer than 2% of all natural diamonds and recognized for exceptional chemical purity.

The diamond was cut from a 114.83-carat rough recovered at the Jwaneng mine, operated by Debswana, a joint venture between De Beers and the Government of Botswana. The mine is widely regarded as the world’s richest diamond source by value, reinforcing the stone’s provenance credentials.

The unveiling took place at Maison Assouline in London, marking the diamond’s first public appearance and forming part of a broader collaboration between De Beers and Sotheby’s. The event coincided with the launch of a publication celebrating the cultural legacy of diamonds, alongside a curated exhibition exploring the intersection of diamonds, art and design.

Sotheby’s has estimated the diamond to achieve between $2.2 million and $2.8 million at auction. The stone will headline the auction house’s Luxury Week sale in Hong Kong, alongside additional diamonds from De Beers’ portfolio.

For De Beers, the collaboration underscores a continued focus on traceability, provenance and storytelling as key value drivers in the natural diamond segment. The structured journey of the stone — from mine to market — aligns with increasing industry emphasis on origin transparency and rarity-led positioning.

The launch also reflects the role of high-profile auctions as platforms for showcasing exceptional diamonds, particularly in Asia, where demand for rare, investment-grade stones remains resilient.