The Williamson Diamond Brooch is “designed in the form of a jonquil set with brilliants, marquises and baguettes, the centre of the flower with a large pink brilliant.”1
The large pink centre stone is 23.6 carats and is believed to be the finest pink diamond to ever be discovered. It was discovered in October 1947 in the Mwadui mine in Tanzania, which was owned by Dr John Thorburn Williamson. He presented the diamond to the then Princess Elizabeth for her wedding the following month.
In early 1948, the diamond was cut as a brilliant and the stone was set in a platinum brooch in 1953. Williamson had wanted to add further pink diamonds to it, but when these were not discovered, he added 170 small brilliant, 12 baguettes and 21 marquises.
Most notably, the late Queen wore the brooch for the weddings of the Prince of Wales and Lady Diana Spencer and Viscount Linley and the Hon. Serena Stanhope and Prince Edward and Sophie Rhys Jones.