Catherine wore Queen Alexandra’s Wedding pearl and diamond necklace for the first time at the Netherlands State Banquet in October 2018. The necklace features 8 pearls surrounded by diamonds, each connected with festoons of diamonds, and three detachable diamond and pearl drop pendants. Queen Mary gave the necklace to Queen Elizabeth The Queen Mother, and she wore it constantly. The necklace was finally reunited with the brooch and earrings when The Queen inherited it in 2002.
It was last seen in 1983, worn by Queen Mother at the state banquet coincidentally hosted by Queen Elizabeth II for the Netherlands King and Queen. Read more about the necklace at Her Majesty’s Jewel Vault here.