World's Most Expensive Diamond Sells For Record Price

It is the ultimate diamond in the rough. And if you have to ask how much it costs, you can't afford it. A rare and flawless blue diamond has set a record as the most expensive precious jewel of its kind ever sold. The gem, which is 6.04 carats and sparkles with an unusual blue hue, is almost as breathtaking as the price it fetched at a Sotheby's auction in Hong Kong. It went for an astounding US$7.98 million, or about $US1.32 million per carat.

That easily surpassed the cost of the previous record holder known as "The Hancock Red", which fetched a "paltry" US$926,000 per carat in 1987.

Blue diamonds are rare but not unheard of and the ones in spectacular condition almost always fetch a huge price. Despite this sale, the most famous remains the Hope Diamond, a 45.52 carat monster that has been owned by everyone from King Louis XIV of France to a rich socialite named Evalyn Walsh McLean. It's the largest gemstone of its kind ever found and now resides in the Smithsonian Institute in Washington, D.C.

The new record holder for price isn't quite as large, so how it could manage to reap those sparkling bucks? Experts say it's all in the quality of the cut and the "fancy vivid blue hue", a result of trace amounts of an element called boron in its crystal structure. That makes it worth about 10 times what a regular white diamond would bring.

So who owns this incredible piece of jewelry? A company called Moussaieff Jewellers in London, which specializes in acquiring such rare specimens, ponyed up the money after a private Asian collector decided he needed a little - or in this case a lot more - cash.

Which just goes to show you don't always need yellow to turn a shade of blue into something green.