The faithfully documented Cartier archives are an invaluable source of inspiration and information for restoration work on old pieces. One example among many of the company's expertise in restoration is the ceremonial necklace of Sir Bhupindar Singh, Maharajah of Patiala.

In 1926, a trunk filled with precious stones and jewelry arrived at the Cartier jewelry workshops in Paris. The Maharajah wished to have the contents reset in the Parisian style. To carry out the work he chose Louis Cartier, the quintessential Paris jeweler, whom he had met in India. The result was a unique piece comprising 2,930 diamonds with a combined weight of 962.25 carats: five magnificent Art Deco diamond-studded platinum chains adorned with seven large diamonds in a variety of cuts (from 18 to 73 carats), suspended in a mesmerizing cascade. The dazzling white ensemble is pierced with flashes of color: one 18-carat tobacco-colored diamond; two Burmese rubies with a combined weight of 29.58 carats; and a stunning 234.69-carat stone, the famed De Beers diamond.

In 1998, the piece was found in London in very poor condition: the largest of the diamonds and the central gemstones were missing, and only the five large diamond-studded platinum chains remained. It had once been the largest, most impressive necklace ever made by Cartier – or indeed any other jeweler. Conscious of the splendid, nostalgia-tinged appeal of the piece, Cartier embarked on an adventure that was unprecedented in the Maison's history.

Substitute gems were provisionally used to restore the dazzling luminosity of the extraordinary piece until such time as fitting replacements could be found. Cubic zirconium stones were set in the place of diamonds and synthetic rubies offered a color similar to the original gems. The Cartier jewelers in Paris succeeded in reproducing the impressive necklace, demonstrating the same delicate craftsmanship that characterized platinum jewelry in the late 1920s. Diamonds and Burmese rubies replaced the synthetic stones and recaptured the original beauty of the piece.

Platinum, antique and rose-cut diamonds (chains and links), zirconium (cubic zirconium oxide), white topaz, smoky quartz, and synthetic rubies. The necklace originally comprised 2,930 white diamonds and the yellow De Beers diamond of 234.65 carats which adorned the central pendant.