Title: Mica/smectite interstratified minerals found in hydrothermally and diagenetically altered rocks.
Abstract: Mica/smectite interstratified minerals are formed from smectite by adding alkali ions and increasing temperature. This transformation starts by increasing the alkali ion content and smectite changes to mica/smectite interstratified minerals with g=0 in the early stage of the transformation. The minerals formed transform to mica/smectite with g=1 by increasing temperature and pressure. On the other hand, mica changes to mica/smectite interstratified minerals by hydrothermal alteration. The minerals formed from mica usually show the interstratif ications with g=1 and 2. Some mineralogical data of the minerals formed by the two processes are given here and we show the considerations showing the formations of the minerals.