Abstract
Kaolinite crystals collected from several localities in Japan were examined in detail by means of X-ray powder technique, with the conclusion that there are marked structural variations in them.
Summarising the results so far obtained, these kaolinites were classified into three types on the basis of degree of crystallinity.
Type (1) Ordered type without randomness.
Type (2) Partially disordered type with some amounts of ± n 1/3 →b random displacements.
Type (3) Partially disordered type with ± n 1/3 →b and some additional random displacements parallel to layers.
It is noteworthy that the degree of orderedness of the minerals is roughly correlated with their modes of occurrence and with their morphological appearances under the electron microscope.
