경주 사천왕사지 녹유전의 녹유 특성 연구

Abstract

This article reports the results of scientific analysis using SEM-EDX, XRD, TG/DTA, performed on 5 green glaze samples of the brick and roofing tile excavated from the Sacheonwang temple site in Gyeongju in order to verify the chemical compositions and melting temperature. The glaze samples on 2 clay statues have similar chemical composition (PbO 74~81%, SiO2 14~18%) and melting temperature range (970~1070℃), whereas the 2 tiles of goblin’s face and 1 rhomb brick have different characteristics. Sample SC 003 (made of PbO 63~67%, SiO2 25~28%), one of the tiles of goblin’s face, shows low melting temperature range (below 970℃), and sample SC 004 (composed of PbO 64~70%, SiO2 19~25% and melting point 970~1070℃), the other tile of goblin’s face, shows different chemical characteristics compared with 2 clay statues. The green glaze on rhomb brick shows different composition compared with all the others from Sacheonwang temple site in that it does not show any impurity elements other than the main components (PbO 87~88%, SiO2 12~13%) with very low melting temperature range (750~770℃). Surprizingly, the chemical and optical characteristics of this green-glaze on rhomb brick are very similar to that on the bricks from Yeongmyo temple site, Gyeongju. The above results indicate that raw material and manufacturing method are not same for 5 green-glaze samples from Sacheonwang temple site and therefore suggests that further study on the provenance of raw material such as lead isotope analysis is necessary. Our work will provide basic data for future reproduction study of green glazed brick of Sacheonwang temple site, Gyeongju and will also serve as a reference data for the study of raw material and manufacturing method of green glaze from other sites of cultural assets