A large fancy colour blue diamond ring will headline Sotheby’s Geneva High Jewellery sale on 12 May and is expected to command a gigantic return. | Source: Sotheby's

A pair of unmounted brilliant-cut, 18.38-carat, D-flawless diamonds, both classified as type IIa. | Source: Sotheby's

102.40-carat Ceylon sapphire known as The Peacock of Ceylon. | Source: Sotheby's

A circa-1950 Cartier bracelet featuring a 7.04-carat Kashmir sapphire. | Source: Sotheby's