That was until 2012 when Queen Camilla (then Duchess of Cornwall) wore the piece to another red carpet moment: the London premiere of Skyfall. Like Catherine, Camilla chose the necklace as a masterly, monochromatic finishing touch to an all-purple ensemble, pairing the pearl-and-amethyst confection with a sumptuous velvet gown.

There are a number of other amethysts in the royal collection – including the ‘Kent Amethysts’, a stunning, diamond-bordered suite most recently worn by Queen Camilla on the state visit to the US. However, the Princess of Wales chose to forgo co-ordinating earrings and instead opted for heirloom earrings that belonged to Princess Diana.

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The necklace was first seen in public in 2012 when it was worn by Queen Camilla to the Skyfall premiere

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Each earring features a round, diamond stud from which is suspended an additional round diamond, a diamond-set bell cap and a large, pearl drop, making them a truly statement piece. Princess Diana was given the earrings by Collingwood, a jewellery firm often favoured by the Spencers, which lent gems to the young Diana while she was engaged to the then Prince Charles.

When Diana posed for a portrait session with Lord Snowdon, Princess Margaret‘s photographer husband, during her engagement, Collingwood lent her an elaborate diamond necklace and matching earrings. Reportedly, the jewellers wanted to gift the two pieces to Diana as a wedding gift, but the Palace cautioned that the set would be considered too extravagant. Instead, they gave her a pair of pearl and diamond earrings.

Diana made her debut in the pearls at a dinner held in honour of King Khalid of Saudi Arabia at Claridge’s in June 1981, several weeks before her wedding. They quickly became a mainstay in her jewellery collection and remained a favourite throughout her marriage. On grand state occasions, the Princess normally paired them with other pearl pieces, such as the Queen Mary Lover’s Knot Tiara.