Analysis of Admixtures Found in Ground Layers of Twelfth-Century Urushi Works

Abstract

In this research, a petrological and mineralogical examination was carried out for the first time to examine the ground layers of Urushi works. The examined samples were two pieces of Urushi coating from Chusonji Konjikido, a building representative of twelfth-century AD Japan. Also examined were two samples from a dish excavated from the Yanaginogosho site. Chusonji Konjikido and the Yanaginogosho government building were built by the Oshu Fujiwara Family, a powerful family who controlled the entire Oshu area. The examination revealed that the admixture of the ground layers of the Konjikido samples consisted mainly of pumice tuff. The dish had ground layers composed mainly of plagioclase and volcanic glass. It was discovered that pumice tuff distributed within the precincts of the Chusonji Temple was used to make the ground layers of the examined urushi works, based on a comparison of the chemical composition of the volcanic glass contained in the urushi works. This material is not used in the modern lacquer-ware industry. The technique for making the ground coating used in the production of Konjikido and the dish is a lost technology.