Historic Diamonds
Rio Tinto’s Final Tender Brings the End of an Era in Argyle Diamonds
By Grant Mobley, Published: September 23, 2025
With Argyle pinks, reds, and violets gone forever and Diavik’s whites and yellows nearing their end, Rio Tinto’s last Beyond Rare™ Tender marks a turning point in diamond history.
Argyle and Diavik Diamonds from Rio Tinto’s Latest Tender
This autumn, a chapter in the history of diamonds will come to a close with Rio Tinto’s final Beyond Rare™ Tender, titled Into the Light. Comprising 52 lots of exceptionally rare colored and colorless diamonds from the Argyle Diamond Mine in Australia and the Diavik Diamond Mine in Canada, this event marks not only the closing chapter of Rio Tinto’s Art Series but also the last time we may ever see diamonds of such extraordinary character offered together.
Meet the Expert
- Grant Mobley is the Jewelry & Watch Editor of Only Natural Diamonds.
- He is a GIA Diamonds Graduate.
- He has over 17 years of jewelry industry experience, starting with growing up in his family’s retail jewelry stores.
With Argyle closing its gates in 2020 and Diavik set to cease operations in 2026, Into the Light is more than a sale. It is a farewell to two of the most storied diamond sources in the world and a celebration of nature’s most remarkable geological creations.
Rio Tinto’s Argyle Diamond Legacy
For over three decades, the remote Argyle Diamond Mine in Western Australia’s East Kimberley region was the sole source of the world’s supply of pink diamonds, producing over 90% of them. Yet even at Argyle, these treasures were astonishingly rare. Pink diamonds accounted for just one tenth of one percent of total production, while reds and violets were rarer still.
What made Argyle’s pink diamonds so captivating was their mysterious origin. Unlike nitrogen, which gives yellow diamonds their color or boron, which gives blue diamonds theirs, pink diamonds owe their hue to structural distortions occurring deep within the Earth. Some 1.8 billion years ago, as the Nuna supercontinent fractured, seismic heat and pressure twisted the diamond lattice structure, bending light in ways that revealed nature’s most elusive palette.
The Into the Light Tender includes the final polished inventory from Argyle’s vaults:
- One Fancy Red diamond certified by GIA,
- 12 Fancy Violet diamonds,
- 76 Fancy Pink, Purple-Pink, and Purplish Pink diamonds
These are more than gems. They are the last whispers of a geological miracle that may never be repeated. For collectors, they represent a chance to acquire diamonds that shaped jewelry history and defined rarity itself.
Rio Tinto’s Diavik Mine and Its Northern Fire
If Argyle’s magic lies in its spectrum of pinks, reds, and violets, then Diavik’s story shines in pristine whites and flashes of vivid yellow. Located 220 kilometers from the Arctic Circle in Canada’s Northwest Territories, the Diavik mine is a marvel of modern engineering. Its diamonds lie beneath a frozen lake, accessible only by an ice road that operates for just eight weeks each year.
From this remote wilderness, Diavik produces some of the world’s most brilliant white diamonds. Even still, D-color white diamonds over three carats represent less than 1% of Diavik’s output, and Flawless clarity is rarer still. Fancy Intense yellow diamonds also make up less than 1% of production and are a vibrant contrast to the mine’s predominantly colorless output.
The Into the Light Tender features two such white diamonds—a 5.11-carat emerald-cut and a 3.02-carat pear-shaped stone—each meticulously cut from the same rough, and both graded D-color and Flawless. Alongside them is a 6.12-carat Fancy Vivid Yellow diamond, a radiant embodiment of Diavik’s geological treasures. Together, these gems highlight the mine’s duality: a source of crystalline purity and unexpected bursts of color, all born from one of the most pristine ecosystems on Earth.
Rio Tinto’s Global Farewell
The 2025 Tender will travel across the globe—launched in Hong Kong on September 17, with viewings in Perth and Antwerp before bids close on October 20. The collection includes:
- Six Masterpieces showcasing the pinnacle of Argyle and Diavik’s production
- 39 single diamonds
- Seven curated diamond sets
- A total weight of 45.44 carats, including four diamonds over one carat
Each lot represents more than polished brilliance. They are tributes to the men and women who worked to bring light from deep beneath frozen lakes and ancient Kimberley rock formations to collectors and connoisseurs around the world.
Patrick Coppens, Rio Tinto’s General Manager of Sales and Marketing for Diamonds, put it best: “It is hard to understate the importance of this final collection from two extraordinarily beautiful places on Earth. No other mining company in the world has custody of such an exquisite collection of diamond colours, shapes, and sizes, and we all pay tribute to the men and women who have worked so hard over many years to bring them to market.”
Why This Final Tender Matters
Natural diamonds are finite. And colored diamonds, especially reds, violets, and pinks from Argyle, are nearly gone. The closure of Argyle in 2020 ensured that no new pink diamonds of this provenance will ever be unearthed. Diavik’s closure in 2026 will similarly mark the end of a remarkable chapter for Canada’s diamond story.
For collectors, this Tender is not simply about ownership. It is about legacy. These diamonds embody geological wonder, human ingenuity, and cultural history. They are the culmination of billions of years of Earth’s processes and decades of pioneering mining operations.
When the final bids close in October, the world will turn a page in diamond history. The colors of Argyle and the brilliance of Diavik will live on, but never again will they gather under the banner of a Tender.
