Scholars at home and abroad have different views on the origin of glass in China. One is the theory of self creation, and the other is the theory of foreign. According to the differences between the composition and manufacturing technology of glass from the Western Zhou Dynasty unearthed in China and those in the west, and taking into account the favorable conditions for the melting of original porcelain and bronze ware at that time, the theory of self creation holds that the glass in China is evolved from the original porcelain glaze, with plant ash as flux, and the glass composition is alkali calcium silicate system, The content of potassium oxide is higher than that of sodium oxide, which is different from that of ancient Babylon and Egypt. Later, lead oxide from bronze making and alchemy was introduced into glass to form a special composition of lead barium silicate. All these indicate that China may have made glass alone. Another point of view is that ancient Chinese glass was handed down from the West. Further investigation and improvement of the evidence are needed.
From 1660 BC to 1046 BC, primitive porcelain and bronze smelting technology appeared in the late Shang Dynasty. The firing temperature of primitive porcelain and bronze smelting temperature were about 1000C. This kind of kiln may be used for the preparation of glaze sand and glass sand. In the middle of the Western Zhou Dynasty, glazed sand beads and tubes were made as imitations of jade.
The quantity of glazed sand beads made in the early spring and Autumn period was more than that in the Western Zhou Dynasty, and the technical level was also improved. Some glazed sand beads already belonged to the scope of glass sand. By the Warring States period, the primary products of glass could be made. Three pieces of blue glass unearthed on the sword case of Fu Chai, king of Wu (495-473 BC), and two pieces of light blue glass unearthed on the sword case of Gou Jian, king of Yue (496-464 BC), king of Chu, in Hubei Province, can be used as evidence. The two pieces of glass on Gou Jian’s sword case were made by Chu people in the middle of Warring States period by pouring method; The glass on the Fucha sword case has high transparency and is composed of calcium silicate. Copper ions make it blue. It was also made in the Warring States period.
In the 1970s, a glass bead inlaid with soda lime glass (Dragonfly eye) was found in the tomb of lady Fucha, king of Wu in Henan Province. The composition, shape and decoration of the glass are similar to those of Western Asian glass products. Domestic scholars believe that it was introduced from the West. Because Wu and Yue were coastal areas at that time, glass could be imported into China by sea. According to the glass imitation jade Bi unearthed from some other small and medium-sized tombs in the Warring States period and pingminji, it can be seen that most of the glass was used to replace the jade ware at that time, which promoted the development of the glass manufacturing industry in the state of Chu. There are at least two kinds of glaze sand unearthed from Chu tombs in Changsha and Jiangling, which are similar to the glaze sand unearthed from Western Zhou tombs. They can be divided into siok2o system, SiO2 – Cao) – Na2O system, SiO2 – PbO Bao system and SiO2 – PbO – Bao – Na2O system. It can be inferred that Chu people’s glass making technology has developed on the basis of Western Zhou Dynasty. First of all, it uses a variety of composition systems, such as lead barium glass composition system, some scholars believe that this is a characteristic composition system in China. Secondly, in the glass forming method, in addition to the core sintering method, it also developed the molding method from the clay mold cast by bronze, in order to manufacture glass wall, glass sword head, glass sword prominence, glass plate, glass earrings and so on.
In the Bronze Age of our country, the dewaxing casting method was used to make bronzes. Therefore, it is possible to use this method to make glass products with complex shapes. The glass beast unearthed from the tomb of King Chu in beidongshan, Xuzhou, shows this possibility.
From the composition of glass, manufacturing technology and the quality of imitation jade products, we can see that Chu played an important role in the history of ancient glass manufacturing.
The period from the 3rd century BC to the 6th century BC is the Western Han Dynasty, the Eastern Han Dynasty, the Wei Jin and the southern and Northern Dynasties. The emerald green translucent glass cups and glass ear cups unearthed in Hebei Province in the early Western Han Dynasty (about 113 BC) were formed by molding. Glasses, glass beasts and glass fragments from the tomb of the king of Chu in the Western Han Dynasty (128 BC) were unearthed in Xuzhou, Jiangsu Province. The glass is green and made of lead barium glass. It is colored with copper oxide. The glass is opaque because of crystallization.
Archaeologists unearthed glass spears and glass jade clothes from the tombs of the middle and late Western Han Dynasty. The density of light blue transparent glass spear is lower than that of lead barium glass, which is similar to that of soda lime glass, so it should belong to soda lime glass composition system. Some people think that it was introduced from the west, but its shape is basically similar to that of bronze spear unearthed in other areas of China. Some experts in glass history think that it may be made in China. Glass Yuyi tablets are made of lead barium glass, translucent, and molded.
The Western Han Dynasty also made 1.9kg dark blue translucent grain glass wall and 9.5cm in size × Both of them are lead barium silicate glass. These show that the manufacturing of glass in the Han Dynasty gradually developed from ornaments to practical products such as flat glass, and had been installed on buildings for daylighting.
Japanese scholars reported the early glass products unearthed in Kyushu, Japan. The composition of the glass products is basically the same as that of the lead barium glass products of Chu state in the Warring States period and the early Western Han Dynasty; In addition, the lead isotope ratios of the tubular glass beads unearthed in Japan are the same as those unearthed in China during the Han Dynasty and before the Han Dynasty. The lead barium glass is a unique composition system in ancient China, which can prove that these glasses were exported from China. Chinese and Japanese archaeologists also pointed out that Japan made glass gouyu and glass tube ornaments with Japanese characteristics by using glass blocks and glass tubes exported from China, indicating that there was a glass trade between China and Japan in the Han Dynasty. China exported glass products to Japan as well as glass tubes, glass blocks and other semi-finished products.
Post time: Jun-22-2021