The Jwaneng 28.88: A Flawless Diamond Heads to Auction

Getting your Trinity Audio player ready...

On the evening of 19 March, Maison Assouline in London played host to a rare convergence of diamonds, art, and cultural memory. De Beers, in partnership with Sotheby’s, unveiled The Jwaneng 28.88 — an internally flawless, D-colour, 28.88-carat round brilliant diamond that will make its auction debut at Sotheby’s live High Jewellery sale in Hong Kong on 23 April 2026, with a pre-sale estimate of $2.2–2.8 million.

The evening doubled as the London celebration for De Beers’ landmark publication, A Diamond Is Forever — The Making of a Cultural Icon, published by Assouline. Guests including actors Archie Madekwe and Nathalie Emmanuel, musician Poppy Ajudha, and model Poppy Delevingne gathered for what amounted to far more than a product launch: a meditation on what endures, and why.

A Stone Millions of Years in the Making

The Jwaneng 28.88 began its journey deep within the Earth’s mantle, carried toward the surface by volcanic eruptions beneath what is now the Kalahari Desert in Botswana. It takes its name from the Jwaneng mine — “a place of small stones” in Setswana — operated by Debswana, the joint venture between De Beers and the Republic of Botswana. The mine is widely recognised as the richest diamond mine in the world by value.

Cut from a 114.83-carat rough, the stone underwent months of meticulous study and planning by De Beers’ master specialists before emerging as a flawless round brilliant. It is classified as Type IIa — the rarest and most chemically pure category of natural diamond, representing fewer than two per cent of all diamonds ever discovered.

Quig Bruning, Sotheby’s Head of Jewels Americas and EMEA, described the stone as “a perfect emblem of De Beers’ unmatched legacy in diamonds,” calling it “a vanishingly rare feat of nature, combined with a masterclass in diamond cutting and polishing.”

A Century of Storytelling

The unveiling was deliberately timed to coincide with a broader cultural narrative. As De Beers marks one hundred years of diamond storytelling in 2026, the evening at Maison Assouline served as a bridge between past and future — setting the stage, too, for the 80th anniversary of one of the most recognised phrases in advertising history.

It was in 1947 that American copywriter Mary Frances Gerety coined “A Diamond Is Forever” for De Beers, a line that would go on to reshape modern ideas of love, commitment, and permanence. The Assouline volume traces that legacy through 240 pages of archival imagery, iconic advertising, and essays that chart how De Beers transformed diamonds from treasures exchanged discreetly among the elite into universal symbols of emotion and aspiration.

The book also features commissioned artworks by figures such as Pablo Picasso, Salvador Dalí, and Raoul Dufy — a reminder that the relationship between diamonds and artistic expression has long been more intimate than we might assume.

Where Diamonds Meet Art

That intimacy was made tangible on the night through a specially curated exhibition by Sophie Oppenheimer, exploring how diamonds have been imagined, reinterpreted, and immortalised through art across generations.

Archival advertising works — including Pierre Ino’s The Miracle of Love (1955) and Treasures of the Heart (1956), alongside Bernard Lamotte’s How Far Its Beam (1943) — were placed in dialogue with seminal artworks: Patrick Caulfield’s Engagement Ring (1963), Edward J. Burra’s Spanish Music Hall (1932), and a portrait of Rita Hayworth by Vik Muniz. Together, they traced a living, evolving conversation between the gemstone and the creative imagination.

Guests were also invited to view special pieces from De Beers London charting the stylistic evolution of diamond jewellery over the past century, culminating in contemporary creations featuring Desert diamond stones in both rough and polished form. The exhibition’s final reveal, naturally, was the Jwaneng 28.88 itself.

Beyond the Auction

The diamond will not travel to Hong Kong alone. Sotheby’s has confirmed that additional De Beers diamonds from the Jwaneng mine will be offered alongside The Jwaneng 28.88, each carrying its own story of origin and provenance.

It is worth pausing on what makes this collaboration distinctive. In a market that increasingly values traceability and ethical sourcing, the partnership between De Beers and Sotheby’s offers something that extends beyond carat weight and clarity grades: a fully documented journey, from the geological depths of the Kalahari to the auction floor in Hong Kong. De Beers’ “Building Forever” sustainability framework — encompassing livelihoods, climate, and nature — provides the ethical backdrop against which this stone’s story unfolds.

Forever, Reconsidered

There is a line in the press release that lingers: “Forever is not about love remaining unchanged, but about honouring the moments that shape us.”

It is a quietly radical reframing of a concept that De Beers itself did more than any other company to define. If “A Diamond Is Forever” once spoke to permanence and possession, its meaning in 2026 has evolved into something more nuanced — closer to memory, to emotional truth, to the things we choose to carry forward.

The Jwaneng 28.88, born from fire and pressure millions of years before any human hand could touch it, now enters a new chapter. On 23 April, in Hong Kong, someone will claim it. But the stone, as De Beers would remind us, was never really waiting for an owner. It was waiting to be seen.