The Blue Moon diamond has attracted worldwide admiration for its flawlessness. Photo: Reuters
By BBC News
A 12.03-carat blue diamond has been auctioned in Geneva for a record $48.4m (£31.7m) to a Hong Kong tycoon.
Joseph Lau confirmed he bought the ring-mounted, cushion-shaped stone for his seven-year-old daughter, renaming it "Blue Moon of Josephine" after her.
Auction house Sotheby's said the sale had set "a new world auction record for any diamond of any colour". It is not the first time Lau, a property billionaire, has bought precious stones for his daughter.
The businessman - who was convicted of bribery and money laundering in 2014 - is also confirmed as the buyer of a 16.08-carat pink diamond, which Christie's sold for $28.5m on Tuesday.
It has been renamed "Sweet Josephine", a spokeswoman for Mr Lau told BBC News. In 2009, he bought another blue diamond for his daughter - the 7.03-carat "Star of Josephine" - paying what was then a record $9.5m.
He was sentenced to five years in jail after his corruption convictions in a Macau court, but has avoided prison by not visiting the territory. There is no extradition treaty between Macau and Hong Kong.
Sotheby's spokesman David Bennett described Wednesday's blue diamond as "magical". "I've never seen a more beautiful stone," he said.
"The shape, the colour, the purity, it's a magical stone and everybody, I think, who put it on their finger thought so."
Two bidders were locked in a telephone bidding war for eight minutes before the hammer went down on Wednesday's sale, correspondents say, with the jewel not exceeding its pre-sale estimate of $35-$55m.
The diamond was found in South Africa in January last year and its striking blue colour is attributed to the presence of the element boron within its crystal structure.
It was named "Blue Moon" to reflect its rarity. Experts say the market for coloured diamonds has become increasingly strong in recent months, with both blue and pink diamonds attracting a lot of attention in jewel sales in Geneva.
Coloured diamonds are among the rarest in the world, even ones that are not particularly vivid or clear. The Graff Pink - a 24.78-carat pink diamond auctioned for $46.2 million in Geneva in 2010 - was the previous diamond world auction record holder.
In 2013 a diamond known as the Pink Star was sold for what was then believed to be a record breaking $83m (£52m) - also at a Sotheby's auction in Geneva. However, the buyer later defaulted on the purchase, and Sotheby's was forced to buy the diamond under its auction contract.