GENEVA (AFP).- A cushion-shaped pink diamond is expected to raise up to $28 million when it goes under the hammer in Geneva on November 10, auction house Christie's said on Thursday.

The 16.08-carat diamond is set as a ring and is sufficiently pink to qualify under Gemological Institute of America guidelines as a "fancy" stone, according to Christie's, which said only three "vivid pink" diamonds of over 10 carats have been up for sale in 250 years.

The stone is classified as a Type IIa diamond, a classification assigned to only two percent of all gem diamonds, Christie's said.

The main diamond is surrounded by two rows of white diamonds, with another row of pink diamonds below. The band of the ring, meanwhile, is made up of more white diamonds set in platinum.

It will go on an international tour beginning next month, being displayed at Christie's locations in Hong Kong, New York and London before going under the hammer.

The world record for the sale of a diamond at auction is currently held by a 24.78-carat pink diamond, known as the Graff Pink, which sold in Geneva in November 2010 for just over $46 million.

But auction house Sotheby's has said it will be auctioning a 12.03-carat blue diamond, which could fetch $55 million when it goes on sale on November 11, also in Geneva, a day after the Christie's auction.



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