Pink Star becomes world’s most expensive diamond after it sells for £51.7million

The massive Pink Star became the world’s most expensive diamond last night after it was sold for £51.7million.

The plum-sized South African sparkler went under the hammer in Geneva and was snapped up by a mystery buyer.

The flawless 59-carat pink diamond is the largest in its class ever graded by US experts.

David Bennett, of the auctioneers Sotheby’s, said: “It’s really extraordinarily rare. Very, very few of these stones have ever appeared at auction.”

The oval-cut rock, found in 1999, measures 2.69 by 2.06cm and weighs almost 12g.

Mr Bennett added: ”The demand for exceptional diamonds keeps on growing.”