Previously in the Report (No. 12, 1963) present writer described the geology of the pyrophyllite deposits in Japan. In the present paper he describes the mineral paragenesis of the deposits.
The main constituent minerals of the deposits are pyrophyllite, kaolinite, diaspore, corundum, andalusite and quartz. The predominant mineral assemblages are pyrophyllite+guartz, pyrophyllite+quartz+diaspore and kaolinite+quartz. Four minerals pyrophyllite, kaolinite, diaspore and quartz constitute the main part of the deposits and are almost contemporaneous in their mineralizations. The minerals are stable and not affected almost any alteration. The mineralization of corundum and andalusite took place locally in the deposits, and precede quartz, pyrophyllite, kaolinite and diaspore mineralizations. Andalusite and corundum are unstable and frequentlly alter to kaolinite, pyrophyllite and diaspore. Exceptionally andalusite in andalusite+quartz assemblage is fresh and not presents any alteration.