Scientific research on color and chemical composition of the ancient glass

本文介绍并讨论了弥生和土剌时期玻璃珠的颜色和化学成分。弥生时代的主要玻璃系统是铅钡玻璃和钾玻璃。大多数的钾玻璃都是浅蓝色和深蓝色。淡蓝色的钾玻璃是用铜着色的，铅和锡含量很低。特别有趣的是深蓝色的钾玻璃。所有的深蓝色钾玻璃珠都是钴色的，锰和铁的含量很高。在日本发现的这些玻璃的化学成分与在中国和韩国发现的玻璃非常相似。许多深蓝色玻璃分布在九州北部，浅蓝色玻璃分布在日本关西地区。另一个有趣的发现是在蓝色铅钡玻璃中存在“汉蓝颜料（BaCuSi_4O_<10>）”。在日本冈山县有本考古遗址出土的公元2 ~ 3世纪的蓝色铅钡管状玻璃中，通过x射线衍射首次发现了汉蓝颜料。到目前为止，无论是在日本还是在韩国和中国，都没有在铅钡玻璃珠中发现汉蓝颜料的报道。

In this research, the color and chemical composition of glass bead in the Yayoi and Tumulus period were presented and discussed.The main glass systems in the Yayoi period were as the presence of lead barium glass and potassium glass. All most of potassium glasses are the light blue and dark blue colored. The light blue potassium glasses are colored with copper and have low content of lead and tin. Especially interesting is the dark blue potassium glass. All the dark blue potassium glass beads are colored with cobalt and have high content of manganese and iron. The chemical compositions of these glasses found in Japan were very similar to those in China and Korea. Many of dark blue glass is distributed in northern part of Kyushu, and the light blue glass is distributed around in Kansai area in Japan.Another interesting discovery is the presence of "Han-blue pigment (BaCuSi_4O_<10>)" in the blue lead barium glass. For the first time Han Blue pigments have been detected by X-ray diffraction in the blue lead-barium tubular bead glass of the second-third century A.D.excavated in Arimoto archaeological site, Okayama prefecture in Japan. So far Han Blue pigments have been reported in lead-barium glass beads neither in Japan nor in Korea and China.