A 26.36-carat round brilliant cut white diamond – the largest to come to market in the UK for over a decade – will go under the hammer on March 17.

The diamond solitaire set in a platinum ring is expected to sell for £800,000 to £1 million (approximately US$1.07 million to US$1.34 million).

Joe Kendrick, head of Sale at UK-based auction house Elmwood's, remarked, “This is an extraordinarily rare diamond. Its combination of size, 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.”

The diamond is graded VVS1 clarity with the best cut, polish and symmetry achievable, according to the auction house. A report by the Gemological Institute of America confirmed the stone’s I colour and no fluorescence. 

Diamonds of this size are extremely rare in the UK. The last comparable sale was a 26.5-carat diamond offered by Sotheby’s in 2017, highlighting the rarity and historical significance of this latest offering. 

“Collectors and connoisseurs are presented with a once-in-a-decade opportunity to acquire a jewel that combines rarity, technical perfection and the enduring allure of one of nature’s most remarkable creations,” the auction house said.

The diamond will headline Elmwood’s Fine Jewellery auction on March 17, 2026.