A unique vivid blue diamond weighing 7.03 carats had been sold on Tuesday for a record 10.5 million Swiss francs ($9.49 million), this is the highest price paid per carat for any gemstone at auction, Sotheby’s said.

This is the rarest item entered the international market this year, whi is went to an anonymous buyer bidding by telephone after hectic bidding see-sawed between two callers for 15 minutes.

It was the centrepiece of its semi-annual sale in Geneva, conducted by David Bennett, chairman of Sotheby’s jewelry department in Europe and the Middle East, who said the results showed the market’s resilience despite the economic downturn.

“This is already a new world record price for a fancy vivid blue diamond and a new world record per carat for any gemstone (at auction),” Bennett told reporters.

“It is fantastic in this market and shows that these rare things are very much in demand,” he said.