Nawanagar ruby necklace

French jewellery house Cartier designed this platinum, ruby and diamond necklace for Maharaja Digvijaysinh of Nawanagar (present-day Jamnagar in Gujarat) in 1937. The Burmese rubies were collected by the king’s predecessor, Maharaja Ranjitsinh. The necklace was sold back to Cartier after 1947, when erstwhile royals were allowed to retain personal possessions but had to turn over their immovable assets to the Indian government. The design has since been altered to suit a woman’s frame.

On view as part of the Al Thani collection at the Hôtel de la Marine in Paris. Built up by Sheikh Hamad bin Abdullah Al-thani, a Qatari prince, over 15 years, the collection spans 6,000 items.