Bunny Mellon’s blue diamond has fetched $32.6 million at an auction in New York, breaking the world auction record for any diamond of its color, Sotheby’s says.

The stunning 9.75 carat, pear-shaped diamond was bought by a Hong Kong private collector after 20 minutes of competitive bidding on November 20.

The price also set a new world auction record for price-per-carat for any diamond, the auction house said.

The jewel had been owned by Rachel Lambert otherwise known as Bunny Mellon, the art collector wife of the late philanthropist and racehorse breeder Paul Mellon. She died in March aged 103.

“Mrs. Mellon’s diamond absolutely deserves the place in the record books that it achieved,” said Gary Schuler, head of Sotheby’s jewellery department in New York.

It was the highlight of a collection of Bunny Mellon’s jewels and other prized objects that Sotheby’s sold for more than $42 million in New York on November 20, well above the pre-sale estimate of $19.2 million.