“The Premier Blue” is expected to set a new price-per-carat record when it makes its auction debut at Sotheby’s Hong Kong on October 7. The exceptional gem is the largest round brilliant fancy vivid blue diamond ever graded by the Gemological Institute of America.
If The Premier Blue meets its pre-sale estimate of $19 million, the internally flawless 7.59-carat gem will establish a new auction record at $2.5 million per carat, the highest per-carat price ever paid for any diamond.
In April, British billionaire Laurence Graff placed the winning bid of $9.5 million at Bonhams' Fine Jewellery sale in London and came away with a 5.3-carat fancy deep-blue diamond Trombino ring. Graff’s blue diamond is the current record holder at $1.8 million per carat.
Named for the famous South African mine where it was unearthed, The Premier Blue features three characteristics that are extraordinarily rare for a colored diamond — its size, fancy vivid color and round shape.
The round brilliant shape is infrequently chosen for a large fancy-color diamond because more than half of the original weight is typically lost in the cutting and polishing process. In the case of The Premier Blue, the cutter decided for opt for maximum brilliance.
Blue diamonds get their color from a rare natural phenomenon when a little bit of boron gets trapped in the carbon crystal structure. It is estimated that one out of 200,000 diamonds found in the world has any hint of a blue color to it, and typically it’s a very pale blue.
Quek Chin Yeow, Sotheby Asia's deputy chairman, said Hong Kong was the natural venue to sell The Premier Blue, because Asian buyers prefer round cuts and fancy-color diamonds.
Prior to the sale, Sotheby’s will be previewing the stone, along with other auction items, in six Asian cities, as well as Geneva, London, New York and Doha.