Containing a total of 2930 diamonds with the De Beers yellow diamond as its centrepiece, the Patiala Necklace was made in 1928 by the Cartier jewellery house in Paris under commission by Maharaja Bhupinder Singh of Patiala (r. 1900–1938). The ruler of the princely state, known for his extravagant tastes and penchant for jewellery, enlisted designer Louis Cartier to create a ceremonial necklace out of his heirloom jewels. Considered among the most expensive and elaborate jewellery ever made, it is estimated to have cost around 30 million USD in present currency value. The necklace’s disappearance around 1948 and the subsequent reappearance of its parts have been subjects of speculation and intrigue. The necklace in its current form is Cartier’s reconstruction over the original base with the missing elements painstakingly substituted.  

The yellow diamond was discovered in De Beers’s South African mine in 1888, weighing over 400 carats in the raw. At approximately 230 carats after it was cushion-cut, it was the seventh largest polished diamond in the world. The then Maharaja of Patiala bought it after it was exhibited at the Paris Universal Exhibition of 1889. Later, it was among the large number of precious stones that Maharaja Bhupinder Singh sent to Cartier in Paris c. 1926, with instructions to create a necklace worthy of his position. Combining South Asian influences with European designs, the necklace comprised five platinum chains in addition to a choker or neck collar. These were entirely encrusted with small diamonds, with seven larger diamonds — each between 18 and 73 carats — as well as some emeralds and Burmese rubies, surrounding the central pendant, which held the De Beers diamond. With a final weight of nearly 1000 carats, the necklace took about three years to complete, and was exhibited in Paris before it was delivered to the Maharaja. 

Bhupinder Singh wore it on several occasions before his death in 1938, after which his son Yadavindra Singh inherited it. The necklace remained in Patiala’s royal treasury until 1948, after which it was discovered to be missing. Thought to have been dismantled and smuggled out of the country after the accession of Patiala to the newly independent union of India, its whereabouts remained unknown for over three decades. In 1982, the De Beers diamond appeared at a Sotheby’s auction at Geneva, Switzerland, but its location thereafter remains undisclosed. In 1998, a jewellery expert associated with Cartier discovered the platinum skeleton of the necklace in an antiques shop in London, with all of the larger stones missing. Having acquired this, Cartier London refurbished the necklace using cubic zirconia and synthetic diamonds to replace the missing gems.