Clay Minerals from the Pottery Stone Deposits in the Cheongsong Area, Kyeongbuk, Korea

경북 청송지역 도석광상에서 산출하는 점토광물

The pottery stone diposits of the Cheongsong area consist of abundant quartz with clay minerals such as mica/smectite interstratified mineral, tosudite, kaolinite and sericite. The occurrence and mineralogical properties of the clay minerals were investigated by X-ray diffraction method, chemical analysis, DTA and IR. The mineral transformation by hydrothermal alteration was also discussed. Tosudite occurs in the Beopsoo pottery stone deposit, it seem to be Li-beraing tosudite. Mica/smectite interstratified minerals with less than about 20% expandable layers are commonly observed in the pottery stone deposits of the area. The mica/smectite interstratified minerals tend to increase the expandable layers as the progress of alteration. The pottery stones from this area seem to be altered from rhyolite or welded tuff by hydrothermal solution.