A Fancy Intense Blue diamond which has been held in a private collection for nearly 30 years sold for $3.6 million, smashing its $2 million high estimate, at Bonhams Fine Jewellery sale in London.

The 4.03-carat pear-shaped diamond was the subject of a fierce bidding frenzy, according to Bonhams, before it went under the hammer, selling to Graff Diamonds for $853,203 price per carat.

Another colored diamond jewel also achieved a strong price. A mid-20th Century Fancy Colored diamond brooch sold for $980,000. The brooch comprised of a 4.83-carat square step-cut Fancy Gray-Blue diamond, two Fancy Dark Brown-Greenish Yellow step-cut diamonds, weighing 2.51 carats and 2.38 carats respectively, and a 1.90-carat pear-shaped Fancy Pink diamond.

The second highest value lot sold at Wednesday’s auction was a 9.61-carat Kashmir sapphire single-stone ring. The octagonal step-cut sapphire has no indications of heating and went under the hammer for $1.1 million, within estimates, equating to $112,600 price per carat.

Kashmir-Sapphire

A 4.61-carat old marquise-cut diamond single-stone ring, D colour, VVS2 clarity, potentially flawless, sold for $160,000, against its high estimate of $134,647.

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Our top lots performed extremely well with global buyers vying for the prize lots,” said Jean Ghika, head of Jewellery, Bonhams UK & Europe. “The blue diamond and Kashmir sapphire both achieved strong hammer prices, demonstrating discerning collectors will always seek out the best examples when it comes to fine gemstones.

The overall sale totaled more than $10.2 million, with 93 percent lots sold by value.