The Williamson Flower Brooch is a jonquil (daffodil-type) flower, featuring a pink diamond at the centre; 23.6k in total, it is the finest pink diamond in the world, according to The Royal Collection.
The piece was designed by Cartier specifically for the large stone, which came from Canadian Dr John Williamson. The doctor owned a mine in Tanzania where the stone was found, hence the name that has stuck to this piece. Williamson gave the diamond to Princess Elizabeth as a wedding gift in 1947 and in it 1953 was made into the flower we see today. He wanted to give more pink diamonds, but none were found in the mine, so he gave clear diamonds to supplement the gift: 170 small brilliant-cut, 12 baguette-cut and 21 marquise diamonds. These were used to form the petals, stem and the leaves of the flower.
The Queen wears her favourite brooches for important occasions, or those with a particular link to the event. The Williamson brooch falls into the former category, and Her Majesty wore it in 1981 to the wedding of Prince Charles and Lady Diana, and then to the wedding of her youngest, Prince Edward, who married Sophie Rhys-Jones in 1999.
As with many of Her Majesty’s brooches, she pairs it with similar toned outfits, in this case pinks and lilacs.