Auction house Christie's says the rare 14.23 carat diamond, named The Perfect Pink, sold for $23,165,968 on Monday in Hong Kong to an anonymous buyer after an intense bidding war with four others. The selling price is higher than the $14 million (£9 million) to $19 million (£12.2 million) it was expected to fetch. It fell short of the $46 million (£29.6 million) another pink diamond measuring 24.78 carats sold for in Geneva in mid-November. That sale smashed the world record for the selling price of a jewel at auction. Christie's says only 18 diamonds bigger than 10 carats and showing a distinct pure pink colour have ever gone on the block in 244 years of auction history.