Many mathematical theories developed for X-ray analysis of interstratified (mixed layer) structure, in which two or more different unit layers are arranged statistically in one dimension, are reviewed and discussed with the determined structure. All the interstratified structures so far reported can be classified into either a regular type or a random one. However, non-integral X-ray superref lections or background elevation often noticed in small angle region can not be explained as due to any one of those types. To solve the problem, a detailed X-ray examination using Kakinoki and Komura's general equation has been tried with reference to its Reichweite and the relevant probability parameters. As the result, it has been disclosed that most of the interstratified minerals are distributed along the line of PBB≅O or PAA≅O on the structure diagram, not along the random line, where PBB and PAA denote the probabilities of B layer next to B layer and A layer next to A layer, respectively. Additional emphasis is put on the extension of the Reichweite in its X-ray analysis as well as the direct observation of layer stacking by a electron microscopy.
