1979 年 14 巻 Special1 号 p. 104-128
There are many hypotheses on the formation mechanism of mixed-layer minerals. In this paper, a formation mechanism of rectorite-type mixed-layer mineral from mica was investigated on the basis of experimental results. Dehydroxylated sericites were transformed into a mica/montmorillonite mixed-layer mineral by various leaching methods with acid solutions, molten LiNO3, sodium tetraphenylboron, sodium cobaltinitrite, and solutions containing salts. By the above procedures, 2M type scricites were easily changed into a regularly interstratified mineral of mica/montmorillonite. A random mixed-layer mineral of mica/montmorillonite was formed from 1M sericite. In order to change the 2M sericitesinto a regularly interstratified mineral, they should be heated up to the temperatur range of dehydroxylation. The formation of a rectorite-type mixedlayer mineral from 2M sericite may be explained on the orientations of the (OH) bonds after release of the potassium ions.