Williamson Diamond Brooch - The centerpiece of this brooch is said to be the finest flawless pink diamond ever discovered. It was found in October 1947 at the Mwadui mine in Tanzania owned by Canadian, Dr John Williamson, who presented the uncut rough 54.5 carats diamond to the then Princess Elizabeth as a wedding gift. It was cut by Briefel and Lemer of London in 1948 into a 23.6 carats piece which was set at the center of the brooch by Cartier along with approximately 200 white diamonds in a 5 petaled flower design with a baguette stem. It is the private property of the Monarch.