A plum-sized diamond known as the Pink Star has fetched a record-breaking $83m (£51.7m) at auction.

Sotheby’s said it was a world record price for a gemstone.

The flawless 59.60-carat pink diamond is the largest in its class ever graded by theGemological Institute of America (GIA), with the second biggest less than half its size.

Set on a ring, it measures 2.69 by 2.06 centimetres and weighs 11.92 grammes.

There was applause as Sotheby’s David Bennett brought down the hammer in the heavily-guarded Geneva salesroom.

Noting that its pre-sale estimate had been $61m (£38m), he told reporters: “It surpassed our estimate. It’s a large amount of money in itself but I don’t think this stone has a price.”

It was bought by a man bidding in the room, who told reporters that he was purchasing it on behalf of an anonymous buyer.

The previous record was held by the Graff Pink diamond which sold for $46.2m (£28.9m) three years ago.

Half the size of the Pink Star, it came from a private collection and had not been on the market for 60 years.

Analysts note that investors have often turned to diamonds and other jewels in uncertain economic times as they are seen primarily as investments.

The Pink Star was 132.5 carats in the rough when it was mined by De Beers in Africa in 1999, according to Sotheby’s.

It was then cut and polished over a period of two years by Steinmetz Diamonds, and was first unveiled to the public in 2003 under the title of the Steinmetz Pink.

Mr Bennett said: “Frankly when I sold the Graff 3 years ago, I thought it would be a record for a very long time. This price is really quite extraordinary three years later.”

source: skynews