Sotheby's auction house has said it will auction off an extremely rare and historically important pink diamond and an equally exceptional Burmese ruby next month, hoping to get up to $18 million for each.

The Historic Pink Diamond, believed to have once belonged to Napoleon's niece, and the deep red Sunrise Ruby figure among a wide range of pieces for sale at Sotheby's spring Magnificent Jewels and Nobel Jewels auction in Geneva on May 12, said a report in the Gulf Daily News (GDN), our sister publication.

The fancy vivid pink diamond, weighing 8.72 carats, is 'extremely rare', the auction house said, pointing to its classic non-modified cushion cut, which is highly sought after but unusual in pink diamonds.

The stone, which is mounted on a ring and sparkles with 'clarity and mesmerising colour', is believed to have been part of the collection of Princess Mathilde, niece of French Emperor Napoleon I, according to the Gemological Institute of America. Sotheby's hopes to rake in $14-18m for the rock.

As for the 25.59-carat Sunrise Ruby, part of a collection of Cartier jewellery available at the auction, GIA described it as 'a unique treasure of nature'.

“In over 40 years, I cannot recall ever having seen another Burmese ruby of this exceptional size possessing such outstanding colour,” David Bennett, head of Sotheby's international jewellery division, said in a statement.

The 'extremely rare' ruby 'is breathtaking in its extraordinary size and outstanding depth of colour,' Sotheby's said. - TradeArabia News Service