Elmwood’s to Offer Rarest Blue Diamond Seen at UK Auction in 18 Years

By Annie Davidson Watson | September 28, 2026

On Oct. 1, a Scottish collector’s 8.03 ct. natural fancy light blue pear-shape diamond will become only the third blue diamond above 8 ct. ever offered at auction in the United Kingdom. Blue diamonds of this size or greater have appeared at British auction exactly twice before: the legendary 70.21 ct. Idol’s Eye at Christie’s in 1865, and the historic Wittelsbach Diamond at Sotheby’s in 2008.

The diamond is estimated at £1.5 million to £2 million (approximately $2 million to $2.7 million) at Elmwood’s Fine Jewelry sale in London. It also is the largest pear-shape blue diamond ever offered at a British auction. Pear shapes are among the more demanding configurations for blue diamonds, requiring cutters to preserve color distribution across an asymmetrical outline.

GIA has graded the stone fancy light blue, natural color origin, VS2 clarity, even color distribution, no fluorescence. This even color distribution means the blue reads consistently across the face of the stone rather than concentrating in certain areas, making it even more valuable.

The color of blue diamonds derives from trace amounts of boron incorporated into the crystal structure during formation—a process that GIA research has shown often occurs at extraordinary depths, with some natural blue diamonds originating in the lower mantle approximately 410 miles below the earth’s surface. They account for less than 0.1% of all diamonds, and that rarity compounds sharply above 5 cts.

The diamond is set as a ring with concentric borders of round brilliant-cut pink and white diamonds and similarly set shoulders—a mounting that frames the pear shape without competing with it.

“To offer only the third blue diamond above 8 carats ever seen at auction in the UK and the largest pear-shaped example is a remarkable moment,” said Joe Kendrick, head of sale at Elmwood’s, in a statement. “We therefore expect wide interest.”

(Photo courtesy of Elmwood’s)

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