Wednesday Christie’s Auction House sold an extremely rare, 17th-century fancy deep grayish-blue diamond for 16.39 million pounds ($24.3 million), a world record price for any diamond or piece of jewelry sold at auction.

The pre-sale estimate was about half the sale price, 9 million pounds.

Famed jeweler Laurence Graff bought the 35.56-carat, historic Wittelsbach diamond, which came to the international market for the first time in almost 80 years, in a highly competitive auction, a Christie’s spokesperson told Reuters.

Large blue diamonds of high clarity, such as this, are very rare. The history of the stone also enhanced its value.

“The importance of the piece, the rarity of it, was recognized,” said Keith Penton, head of Christie’s jewelry department in London.

He said there was strong interest in the diamond from jewelers and private collectors.

The diamond, which was found in an Indian diamond mine, was part of the dowry of the Infanta Margarita Teresa (1651-1673) upon her engagement to Leopold I of Austria.

Four armed robbers pulled off one of the world’s biggest jewelery heists at famed Paris Jeweler Harry Winston, making off with diamonds and valuables worth $108 million dollars, investigators said Friday.The robbery took place Thursday and the men stole nearly all the jewelery on display.

The heist was well-planned, a source from the investigating team told the press. The men knew the names of some of the shop’s employees and the location of some hidden storage cases for jewels.

Two of the men were disguised as women when they managed to elude the high-security surveillance system and burst into the boutique at 5:30 pm on Thursday during the busy holiday shopping season.

Brandishing weapons, they threatened some of the dozen employees and customers and herded them into a corner, while some of the personnel suffered blows, according to investigators.

Police said they were dealing with “major pros” who had meticulously planned their crime and knew the boutique’s lay-out well, suggesting it may have been an inside job.

The thieves, who apparently were French, stuffed rings, necklaces and other finery in bags and quickly left, without firing a single shot.

No leads were ruled out including the possibility that the robbers may have connections in eastern Europe, where the loot could be sold, contrary to western Europe where such high-value stolen goods would be quickly detected.

Police described the eastern European market as a “new El Ddorado for traffickers” trying to get rid of high-end stolen goods.

Police on Friday were questioning customers, employees and pedestrians to try to come up with leads.

Harry Winston, which specializes in ultra-luxury jewelery, was hit by another heist in October last year when armed robbers stole an estimated 20 million worth of valuables.

An insurance company offered a 500,000-dollar reward for information leading to the thieves’ arrest but they were never found.

The US jewelry chain has stores across the world and has sold precious stones to royal families and lent them to film stars for events such as the Cannes film festival or the Oscars in Hollywood.