A rare 26.36 carat round brilliant-cut white diamond is set to headline a major jewellery auction in London, where it is expected to sell for more than $1 million, highlighting continued global demand for exceptional natural diamonds.

The impressive stone will appear in the upcoming Fine Jewellery sale at Elmwood’s, carrying a pre-sale estimate of £800,000 to £1,000,000 (approximately $1.07 million to $1.34 million). The diamond features VVS1 clarity and I colour, placing it firmly within the category of high-quality investment-grade stones sought by collectors and connoisseurs.

To emphasise the diamond’s exceptional brilliance, the stone is set in a simple platinum solitaire ring, allowing the size and quality of the diamond to remain the central focus.

Of particular importance to collectors is the stone’s “Triple Excellent” grading—the highest possible standard for cut, polish and symmetry. The diamond also shows no fluorescence, a characteristic that helps preserve the stone’s natural brilliance and fire under a wide range of lighting conditions.

According to Joe Kendrick, Head of Sale at Elmwood’s, diamonds of this calibre rarely appear on the U.K. market.

“Stones combining this level of size, VVS1 clarity and triple excellent cut are extraordinarily rare in the United Kingdom,” Kendrick noted. “A diamond of this magnitude may only appear once in a decade. This solitaire is a remarkable example of why large white diamonds remain among the most prized gemstones in the world.”

The last comparable stone offered at auction in the U.K. was a 26.27 carat white diamond sold by Sotheby’s in 2017 for £656,750. Known as the “Tenner Diamond,” the stone gained international attention after it emerged that the owner had originally purchased it for just £10 at a car boot sale.

The upcoming auction marks an important moment for Elmwood’s, a relatively young auction house founded in 2017 and based in Notting Hill, London. The firm has positioned itself as a challenger in the international jewellery auction market by introducing a 0% seller’s commission, a strategy designed to attract high-value consignments that might otherwise be directed to the larger auction centres of Geneva or New York.

Large natural diamonds of 25 carats and above rarely appear at auction outside these major global hubs, making this London offering particularly noteworthy for collectors and the broader international diamond market.

For the global trade and collectors alike, the sale reinforces the enduring appeal of large natural diamonds with exceptional cut quality, a segment where rarity and provenance continue to drive value in the high-end gemstone market.