section_path: Prizes/Medals
section_name: Medals
paragraph_text: Medals
  
  The Nobel Foundation announced on 30 May 2012 that it had awarded the contract for the production of the five (Swedish) Nobel Prize medals to Svenska Medalj AB. Between 1902 and 2010, the Nobel Prize medals were minted by Myntverket (the Swedish Mint), Sweden's oldest company, which ceased operations in 2011 after 107 years. In 2011, the Mint of Norway, located in Kongsberg, made the medals. The Nobel Prize medals are registered trademarks of the Nobel Foundation.
  
  Each medal features an image of Alfred Nobel in left profile on the obverse. The medals for physics, chemistry, physiology or medicine, and literature have identical obverses, showing the image of Alfred Nobel and the years of his birth and death. Nobel's portrait also appears on the obverse of the Peace Prize medal and the medal for the Economics Prize, but with a slightly different design. For instance, the laureate's name is engraved on the rim of the Economics medal. The image on the reverse of a medal varies according to the institution awarding the prize. The reverse sides of the medals for chemistry and physics share the same design.
  
  All medals made before 1980 were struck in 23 carat gold. Since then, they have been struck in 18 carat green gold plated with 24 carat gold. The weight of each medal varies with the value of gold, but averages about 175 grams (0.386 lb) for each medal. The diameter is 66 millimetres (2.6 in) and the thickness varies between 5.2 millimetres (0.20 in) and 2.4 millimetres (0.094 in). Because of the high value of their gold content and tendency to be on public display, Nobel medals are subject to medal theft. During World War II, the medals of German scientists Max von Laue and James Franck were sent to Copenhagen for safekeeping. When Germany invaded Denmark, Hungarian chemist (and Nobel laureate himself) George de Hevesy dissolved them in aqua regia (nitro-hydrochloric acid), to prevent confiscation by Nazi Germany and to prevent legal problems for the holders. After the war, the gold was recovered from solution, and the medals re-cast.