7$\AA$ Phase in the Sancheong Kaolin : 7$\AA$-Halloysite or Kaolinite\ulcorner

산청 고령토중의 7$\AA$ 상에 대한 연구 : 7$\AA$-할로이사이트 또는 캐올리나이트\ulcorner

The X-ray diffraction and electron microscopy study of the kaolin sample from Sancheong area show that the halloysite occurs as hydrated 10$\AA$ form. It implies that the 7$\AA$ reflection and hk-line splitting in the X-ray diffractogram are ascribed to kaolinite. Kaolinite in Sancheong kaolin is of a disordered type. It tends to be enriched in the colored part of kaolin samples. Quantitative analyses show that kaolin contains 16-57% halloysite and 10-55%kaolinite.