A extraordinary blue diamond has sold for a record 10.5 million Swiss francs ($9.5m; £6.2m) at public sale in Geneva.

It weigh 7.03 carats and is one of only a handful of blue diamonds in existence.

The unidentified phone bidder has yet to name the gem, mounted on a platinum ring.

The diamond was found in the Cullinan mine in South Africa last during 2008 and its clarity was graded as flawless - the highest designation diamond can get..

Auctioneer David Bennett said: “It is a new world record price for a blue diamond.”

It had a pre-sale catalogue estimate of 6.8 million to 10 million francs.

The hammer  fetched a price excluding commission was 9.3 million francs.

The scarcity of the gems is in part down to the fact so few places in the world mine for blue diamond’s of this kind.
The final sale fetched over $1 million per  ct compare to last year’s sales of  $360 000 per ct of diamonds sold in similar category . A record Price