電子顕微鏡法による日本粘土学会参考粘土試料の評価(I).

The four smectite clays in the CSSJ reference samples have been examined using TEM/STEM imaging and energy dispersive X-ray spectroscopy (EDS) in SEM and STEM, to characterize their chemical compositions, grain sizes, impurity minerals, and other properties. Fine calcite particles were commonly found along with quartz in the Tsukinuno samples (JCSS-3101, 3101b), which serve as the primary source of calcium as reported in previous bulk analyses. Cristobalite, quartz, and feldspar are prevalent impurity minerals in the Mikawa sample (JCSS-3102), and the STEM-EDS analysis revealed that the composition of the smectite clay is definitely montmorillonite with subtle difference from the Tsukinuno montmorillonite. The synthetic saponite (JCSS-3501) displayed a wide range of crystal sizes. Sulfate and sodium ions are concentrated in the aggregates of very fine saponite crystallites compared to the saponite particles with larger sizes. [ABSTRACT FROM AUTHOR]