Abstract
The purpose of this paper is to distill current and future directions of research on interstratified illite/smectite minerals by overviewing the research history. Considerable amount of information on the illite/smectite has been accumulated by previous researchers. At present, clay mineralogists are devoted to constructing the most reasonable model for the mechanism and kinetics of smectite-to-illite conversion on the basis of the previous information. More recent reseach appears to lead us to the final goal for understanding the reality of interstratified mineral in the near future. However, a discovery always offers us new and more difficult problems, as described in the long research history of the mineral. From this viewpoint, the study of illite/smectite may be a paradigm for clay science.
