Some useful links International Union of Crystallography European Crystallographic Association International Union of Pure and Applied Physics (IUPAP) International Union of Pure and Applied Chemistry (IUPAC) Other links      British Crystallographic Association      American Crystallographic Association      DGK - Deutsche Gesellschaft fuer Kristallographie      Association Française de Cristallographie      The Mineralogical Society      Crystallographic software and servers      Various crystallographic links      Steffen Weber Page      Software and On-Line Resources for Crystallography Education      Mineral Collectors Page