The frenzy over Pomellato reached a fever pitch outside of Italy in 2001 with the advent of the Nudo, a weighty gold ring with a huge faceted colored stone set like a diamond solitaire.

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In his 32-carat apricot-color diamond ring, the stone is held in place by threads tied on either side in delicate diamond-shape knots.

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The stone is the largest reddish orange diamond ever graded at the Gemological Institute of America.

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In addition, Ahluwalia also designed a new engagement ring for Royal Asscher called Legacy in which the signature Asscher cut diamond serves as the center stone of the platinum wave-like ring, with diamonds of different cuts detailing each side of the ring.

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The pressure on Mr Agius and Mr Diamond intensified when Barclays' shares dropped like a stone earlier today: at one point it was 18% lower.

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The shape of the stone, likely dating back to the later 16th century, is a product of "diamond-cutting in its infancy, " he says.

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I'm standing at a first-floor window, an arched stone one like you'd find in a church, my face close up to the diamond-shaped leaded panes, keeping lookout.

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The diamond was found in Tanzania in 1947 by the Canadian geologist Dr JT Williamson, who gave the uncut stone to Princess Elizabeth for her wedding in November that year.

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