Sotheby’s to Offer 28.88-Carat Internally Flawless Diamond from Botswana’s Jwaneng Mine with $2.8 Million Estimate
Sotheby’s is set to auction a rare 28.88-carat diamond sourced from De Beers’ flagship Jwaneng Mine in Botswana, with the gemstone expected to achieve up to $2.8 million at sale.
The stone, named the Jwaneng 28.88, is a round brilliant diamond graded D color the highest classification for colorless diamonds and internally flawless, placing it among the rarest categories of polished stones in the global market.
It will headline a high-profile jewelry sale scheduled for April 23 during the auction house’s annual luxury week in Hong Kong.
According to the companies involved, the polished gem originated from a 114.83-carat rough diamond discovered at the Jwaneng mine, widely recognized as one of the world’s richest diamond deposits by value.
Expert cutters from De Beers transformed the rough stone into its final polished form following several months of technical analysis, mapping and precision cutting to maximize brilliance, symmetry and value.
Industry representatives highlighted the significance of the stone as both a natural rarity and a demonstration of advanced diamond craftsmanship. Quig Bruning, Head of Jewels for the Americas and Europe, the Middle East and Africa at Sotheby’s, described the gem as a symbol of the company’s longstanding heritage in the diamond sector, combining exceptional geological rarity with highly specialized cutting expertise.
Ahead of the auction, Sotheby’s and De Beers unveiled the diamond at Maison Assouline in London.
The showcase coincided with the launch of the book A Diamond Is Forever: The Making of a Cultural Icon 1926–2026, published by Assouline, which explores the cultural and commercial evolution of diamonds over the past century.
The celebration featured a curated exhibition by Sophie Oppenheimer, alongside a display of archival and contemporary pieces from De Beers London.
The exhibition traced the stylistic development of diamond jewelry design across generations, highlighting the enduring influence of diamonds in global luxury markets.
