The Williamson pink diamond is a flawless pink diamond set in a brooch that is part of the Royal Collection.
[1] A month later, the owner of the mine, Canadian geologist John Williamson, gave the uncut stone to Princess Elizabeth as a wedding present.
[2] In 1948, the princess and her grandmother, Queen Mary, visited the London diamond cutters Briefel and Lemer to watch the diamond being cut into a 23.6-carat (5 g) round brilliant.
[1] In 1952, the pink diamond became the main feature of a 4.5-inch (11 cm) platinum brooch designed by Frederick Mew of Cartier, at the centre of a jonquil-shaped flower with five petals and two leaves of noisette-cut diamonds and a stalk of baguette cut diamonds.
[1][2] In 2022, a similar pink diamond from the same mine but half the size (11.15 carats) was sold at an auction for $57.7 million.