Rare 26-Carat Diamond Heads to Auction With £1 Million Estimate

A 26.36-carat round brilliant white diamond carrying an estimate of £800,000 to £1,000,000 will go under the hammer at Elmwood's Fine Jewellery auction on March 17, 2026, catalogued as Lot 8. The stone is, by the auction house's own assessment, the largest white diamond to come to market in the UK in more than a decade.

The gemological credentials are formidable. Graded VVS1 for clarity, with I colour and no fluorescence confirmed by a Gemological Institute of America report, the diamond achieves what the trade calls a triple excellent cut: the best cut, polish and symmetry assessable by GIA standards. At 26.36 carats, the round brilliant is set in a simple platinum ring sized L½/6, a mount designed, in Elmwood's words, to "showcase its extraordinary brilliance and fire" rather than compete with it. That restraint is itself a statement: the stone needs no architectural distraction.

"This is an extraordinarily rare diamond," said Joe Kendrick, Head of Sale at Elmwood's. "Its combination of size, VVS1 clarity and triple excellent cut is something you simply do not see in the UK market. Stones of this calibre come along perhaps once in a decade and this solitaire is a spectacular example of what makes white diamonds so prized by collectors worldwide."

The historical point of comparison sharpens the rarity claim. The last comparable offering on British soil was a 26.5-carat diamond presented by Sotheby's in 2017, which means nearly nine years have passed without a white diamond of this scale reaching the UK auction market. Elmwood's described the opportunity as "a once-in-a-decade" moment to acquire "a jewel that combines rarity, technical perfection and the enduring allure of one of nature's most remarkable creations."

Elmwood's, established in 2017 in London's Notting Hill, conducts both live and online auctions for luxury jewellery. The March 17 sale is set to be its most significant to date on the basis of this single lot alone. National Jeweler has noted the stone is expected to top $1 million, reflecting the pre-sale confidence surrounding a diamond that, at this size and grade combination, rarely surfaces anywhere, let alone in a market of this scale.

What makes the piece genuinely notable beyond the headline carat weight is the coherence of its grading profile. I colour sits within the near-colourless range and, crucially, the absence of fluorescence means the stone will not appear milky or hazy under ultraviolet light conditions. Paired with VVS1 clarity, where inclusions are visible only under 10x magnification to a trained grader, the result is a diamond that performs as well as it measures.