Gem-set and diamond sautoir by Bulgari

Diamond necklace by Harry Winston

Fancy vivid blue diamond earrings

A curated selection of rare diamonds, coloured gemstones and signed pieces from prestigious jewellery houses are headlining Sotheby’s Magnificent Jewels and Noble Jewels auction on November 15 in Geneva.

The signed jewels are from illustrious jewellers Harry Winston, Cartier, Van Cleef & Arpels, Bulgari and Pederzani, according to Sotheby's.

Speaking ahead of the sale, Worldwide Chairman of Sotheby’s International Jewellery Division David Bennett, commented, “Our autumn sale offers a carefully curated selection of jewels, which have resonated with jewellery lovers and connoisseurs the world over. We are thrilled to be presenting sensational diamonds – both coloured stones and extremely fine D-colour white diamonds – as well as vibrant coloured gemstones and signed pieces, to complement the finest of jewellery collections. It has been a pleasure for our team to bring together these extraordinary natural treasures, brought to life by the artistry and skill of the world’s finest diamond cutters and jewellers.”

Fancy vivid blue is the most sought-after hue for blue diamonds, which are already enormously rare, according to the auction house. Among the auction’s highlights is a pair of earrings weighing 2.61 and 3.06 carats respectively, valued at US$8 million to US$10 million.

Another featured lot is a ring with a fancy vivid blue rectangular cut diamond of 5.04 carats, priced at US$9 million to US$12 million.

Other highlights include a Harry Winston diamond necklace with nine large diamonds that have been certified as D-Colour and IF with a pre-sale estimate of US$4.8 million to US$5.8 million; and a Harry Winston diamond brooch.

In the coloured gemstone arena, Sotheby’s is presenting a remarkable Burmese sapphire weighing 69.99 carats, mounted as a ring by Cartier. Exceptional Kashmir sapphires as well as ruby and diamond pieces are also on offer.

A one-of-a-kind gem-set and diamond sautoir by Bulgari is another star lot. "Supporting a pendant set with a carved emerald weighing 127.35 carats, it epitomises the richly decorative statement pieces for which the Italian jeweller is so well known. The central gemstone was discovered in Colombia, the most coveted of all geographic locations for emeralds," the auction house said.