An employee uses a brush to clean a bronze medal manufactured for the 2014 Winter Olympic Games in Sochi, at the Adamas jewellery factory in Moscow, June 28, 2013. The factory is the official medal supplier of the 2014 Winter Olympic and Paralympic Games in Sochi. According to the factory, the production of all the series of medals for the 2014 Winter Olympic Games required not less than 3 kilograms of 999 purity gold, 2 tons of 960 purity silver and 700 kilograms of bronze. [Photo/Agencies]