Abstract
The pottery stones, named “Tarumizu Toseki” are found in Osumi peninsula, Kagoshima Prefecture.
In this paper, the results of their chemical analyses, mechanical analyses, X-ray analyses, electron microscopic observation and other various thermal tests were discussed.
The results are as follows,
(1) Main components of Tarumizu pottery stone are orthoclase, albite, quartz (including some cristobalite, and chalcedony), sericite (including illite), and hydro-hall-oysite (including meta halloysite), while it is entirely devoid of kaolinite.
(2) The mixtures of clayportion and fine grains of this stone are suitable for vitreous porcelain bodies. The medium grains are possible to substitute the commercial feldspars in ceramic use, The coarse grains contain a little amount of coloured impurities.
