A knowledge of clay is important in many spheres of scientific endeav our, particularly in natural sciences such as geology, mineralogy and soil science, but also in more applied areas like environmental and mater ials science. Over the last two decades research into clay mineralogy has been strongly influenced by the development and application of a num ber of spectroscopic techniques which are now able to yield information about clay materials at a level of detail that previously would have seemed inconceivable. This information relates not only to the precise characterization of the...