Approximately 4,700 Olympic and Paralympic medals were produced by the Royal Mint at Llantrisant. They were designed by David Watkins (Olympics) and Lin Cheung (Paralympics). 99% of the gold, silver and copper was donated by Rio Tinto from a mine in Salt Lake County, Utah in the U.S. The remaining 1% came from a Mongolian mine. Each medal weighs 375–400 g (13.2–14.1 oz), has a diameter of 85 mm (3.3 in) and is 7 mm (0.28 in) thick, with the sport and discipline engraved on the rim. The obverse, as is traditional, features Nike, the Greek goddess of victory, stepping from the Panathinaiko Stadium that hosted the first modern Olympic Games in 1896, with Parthenon in the background; the reverse features the Games logo, the River Thames and a series of lines representing "the energy of athletes and a sense of pulling together". The medals were transferred to the Tower of London vaults on 2 July 2012 for storage.
Each gold medal is made up of 92.5 percent silver and 1.34 percent gold, with the remainder copper. The silver medal (which represents second place) is made up of 92.5 percent silver, with the remainder copper. The bronze medal is made up of 97 percent copper, 2.5 percent zinc and 0.5 percent tin. The value of the materials in the gold medal is about £410 (US$644), the silver about £210 (US$330), and the bronze about £3 (US$4.71) as of 30 July 2012.