汝州东沟窑金元时期青瓷与钧瓷原料和工艺特征的比较研究

金元时期在豫西中部地区多个窑址同时生产青瓷和钧瓷,发掘于2005年的汝州东沟窑遗址即是该类窑址典型代表之一。为系统了解东沟窑青瓷和钧瓷的胎釉元素组成特征和工艺特点、揭示两类瓷器各自随时代变化的规律,本项研究采用EDXRF和OM对东沟窑遗址出土且地层明确的43件金、元时期青瓷与钧瓷标本胎、釉化学组成和工艺性能进行测试分析,探讨了胎、釉的原料配比、釉层厚度和胎釉反应层厚度等工艺特征随时代和标本类型的变化规律。研究结果表明:东沟窑同时期青瓷和钧瓷胎体元素组成较接近,而两者釉的元素组成差异明显,金元钧瓷釉的SiO2/Al2O3摩尔比值都明显高于同时代青瓷的相应比值,呈现钧瓷釉典型的高硅低铝组成特征。从金代到元代,东沟窑青瓷和钧瓷釉都呈现从钙釉向钙-碱釉的转变。本项研究还观察到金元钧瓷的釉层和反应层厚度均高于同时代的青瓷;而从金过渡到元,两类瓷片的釉层和反应层厚度均趋厚。本项研究对揭示金元时期豫西中部地区青瓷和钧瓷间的传承和演化关系提供了有意义的科技数据。

Comparative study of raw materials and craftsmanship between the celadon and Jun wares of the Jin and Yuan dynasties from the Donggou kiln site in Ruzhou city

During the Jin and Yuan dynasties in the central part of the western Henan province, a number of kiln sites produced both celadon and Jun wares. The Donggou kiln site in Ruzhou city, excavated in 2005, is typical of them. In order to understand the characteristics of the chemical composition and the technology for both celadon and Jun wares from the Donggou kiln site, and to trace their development with time, 43 pieces of celadon and Jun ware sherds from known strata were analyzed by energy dispersive Xray fluorescence (EDXRF) and optical microscopy (OM). This study shows a close similarity in the body compositions for both the celadon and Jun wares in the same period, and also that only minor changes occurred before and after the dynasty transition. On the other hand, significant changes in glaze composition were detected with the dynasty transition. The calcium glaze of the Jin dynasty was replaced by the calcium-alkali glaze of the Yuan dynasty. Also a difference in glaze composition was observed between the Donggou celadon and Jun wares in both the Jin and Yuan Dynasties, namely a significantly higher SiO₂/Al₂O₃ molar ratio in Jun wares than in celadon wares. This is crucial to the liquid phase separation in glaze that endows the Jun wares with a pleasant opalescent appearance. Statistically significant differences in the glaze thickness and the glazebodyreaction layer thickness among the four categories of sherd samples are observed and discussed. This work may offer a better insight into the relationship and evolution of these two porcelain types in the central part of western Henan province during the Jin and Yuan dynasties.