(IDEX Online) - The first of eight stones from the De Beers Exceptional Blue Collection to be offered at auction remains unsold after it failed to reach its minimum.
The 5.53-carat cushion brilliant-cut fancy vivid blue carried an estimate of $11m to $15m and was the headline lot at Sotheby's Geneva Magnificent Jewels and Noble Jewels auction.
It is part of a collection of just over 32 carats recovered from Petra's historic Cullinan mine, in South Africa which are being over the coming months in Geneva, New York and Hong Kong.
Highlight of the collection is the De Beers Exceptional Blue 11.29, a step-cut fancy vivid blue, weighing 11.29 carats, with estimates of $28m to $50m. The value of the whole collection, based on Sotheby's high estimates, is $85m.
Two more blue diamonds from the collection will be offered for sale at Sotheby's New York Magnificent Jewels sale on December 7.
Pic courtesy Sotheby's