The buyer has remained anonymous and the bid was made over the telephone.
Sotheby's auction house say that the diamond, of flawless clarity, has yet to be given a name but describe it as being mounted on a platinum ring.
The very rare gemstone had originally been discovered in the Cullinan mine in South Africa in 2008.
Auctioneer David Bennett explained that the price the diamond was sold for has established a new world record.
The blue diamond had been estimated at a value of 6.8 million to 10 million francs, not including commission before it went up for auction, however, the price it went for, excluding commission, was an incredible 9.3 million francs.
