Ancient glass from the Silk Road

THE MAJORITY OF THE PAPERS in this volume originate from the field of archaeometry – the application of scientific techniques to the analysis of archaeological material, in this case ancient glasses. The compositions of glasses vary in terms of period and region and the study of their chemical compositions has proved to be an important and useful tool. The categorisation of ancient glass into diff erent glass families or glass systems is based mainly on the intentional use of different fluxing agents in the primary process of making glass. These fluxes off er valuable information about the period and region in which a glass originated. It may also allow important conclusions about trade and trade routes. The basic distinction into glass families may be further refi ned through studies of trace elements, lead-isotope analyses and strontium-isotope analyses, which provide a valuable supplement for classifying glasses according to geographical origin (chapters 3 and 4 by Robert Brill).

Space does not allow a review of each of the contributions in detail. Where it seems appropriate, some of the chapters will be outlined together in a larger thematic context. The first two, rather substantial, contributions by Gan Fuxi set the stage and together comprise almost a quarter of the book. In Chapter 1 Gan Fuxi gives an overview of the origin and development of ancient Chinese glass from 'faience' and frit beads (1100-800 BCE) and the earliest glasses (500-400 BCE) through the historic periods up to 1900. Chinese glass production relied mainly on two kinds of fluxing agents: lead and potash (saltpetre was probably used for potash), producing different glass compositions in certain periods. Gan Fuxi’s timeline of Chinese glass distinguishes fi ve diff erent periods: (1) He suggests the few early fi nds of potassium alkali glass (500-400 BCE) originate from Central China. More detailed quantitative analysis would be welcome for future research in this regard. (2) The second or Han period (400 BCE -200 AD) reveals the characteristic Chinese lead-barium glass production generally thought to be located in the Yangzi River valleys and a potash glass which prevailed in the southern and southwestern regions during this period. (3) Post- Han period lead glasses (200-700 CE). (4) potash-lead glass (600-1200 CE). (5) potash lime glass (1200-1900 CE).

In Chapter 2 Gan Fuxi presents an overview of the several routes subsumed under the term the Silk Road, presenting analyses of glass fi nds from the Warring States period to the Yuan Dynasty, the discussion focusing on the early periods and early trade connections. Four different Silk Roads are discussed together with the glass objects found in their areas: Firstly, glass finds in the area of the 'Northern (Steppe) Route' show the wide distribution of glasses made in inner China and in the West; a late highlight are the Islamic glass vessels from an early 11th century tomb. Secondly, along the 'Northwestern (Oasis) Silk Road' glass finds from Kiziltur, Xinjiang, dated to 1100-800 BCE, are considered to be local produced but with Western Asiatic glass technology. For the Qin and Han periods, defi nite imports of Mediterranean and Western Asiatic glass are documented, as well as the spread of Central Chinese lead-barium glass to the western part of Xinjiang. Later, Sasanian and Islamic glasses were imported along this route. Thirdly, the 'Southwestern (Buddhist) Silk Road'; here the Sichuan-Yunnan-Burma-India route is represented by finds of lead-barium glass, potash glass, and a few finds of western soda lime glass in Yunnan and Guizhou from the Warring States to the Six Dynasties periods. Finally, the section on the 'Southern (Sea) Silk Road' deals with glasses found in Guangxi and Guangdong. Hepu in Guangxi was the seat of the Hepu commandery in the Han period and a fl ourishing harbour and starting point for the maritime Silk Road. Most of the Han period glasses unearthed in Guangxi are potash glasses, many with characteristic Chinese shapes and therefore considered to be locally made, whereas those from Guangdong are mostly lead-barium glass. Both types of glass were probably also exported overseas through the ports of Guangdong and Guangxi. From the Six Dynasties to the Tang period a number of imported glass vessels of Mediterranean and Western Asiatic origin attest to the activity of the ports of southern China, from where such imported glasses might also have been transported north into central China.

A large proportion of the other papers in this volume are devoted to detailed studies on glass fi nds along the 'Northern' and 'Northwestern Silk Roads' and their chemical analyses. Chapters 3 and 4 by Robert Brill present fi nds from Afghanistan to Xinjiang with some Central Asian glass compositions of plant-ash soda lime or mixed-alkali glasses. Chapters 7 and 8 by Abdugani Abdurazakov focus on fi nds from Uzbekistan, which reveal a variety of Central Asian glass compositions from the ancient and mediaeval periods and later. Chapters 11, 13-18, by several Chinese scientists and archaeologists, present glass artefacts and their analyses found in northern provinces such as Xinjiang, Gansu, Shaanxi, Inner Mongolia etc., which allow interesting conclusions on early trade connections. Chapter 19 by An Jiayao discusses the earliest blown Chinese glass vessels found in Northern Wei contexts of the 5th century CE. Referring to a passage on the Western Lands in the Bei shi, she suggests that the technique of glassblowing was introduced to northern China by immigrant Central Asian craftsmen from Bactria (the country of the Dayuezhi), who settled in the Datong area. Several papers deal with glass fi nds along the 'Southern Silk Road'. Chapters 5 and 6 by Insook Lee set the stage for the Silk Road of the Sea with emphasis on the maritime bead trade. 

By the late first millenium BCE, Southeast Asia was part of a world trading system linking the civilisations of the Mediterranean Basin and Han period China. The maritime network is seen as extending to Korea and Japan, where a similar diversity of glass compositions compared to those found in China occur. Chapter 9 by Koezuka and Yamasaki deals with early potash glasses in Japan dated to a period from the 3rd century BCE to the 3rd century CE. In Chapter 10 Akiko Hokura et al. investigate the glass reliquary in the Toshodaiji in Nara, examined with a portable XRF spectrometer; the results suggest an Islamic plant ash glass. Chapter 20 by An Jiayao presents new fi nds of Islamic glassware found in 10th century contexts in Guangzhou, representing the extent of imports through the port of Guangzhou. Chapters 21 (Li Qinghui et al.), 22 (Fu Xiufeng and Gan Fuxi), and 23 (Ma Bo et al.) with numerous analyses of glass artefacts found in southern and southwestern China make an important contribution to our knowledge of the extent and frequency of distribution of potash glass and its coexistence with leadbarium glass. Among Han period glasses from Hepu in Guangxi povince, potash glass by far predominates (Chapter 21) indicating – in conjunction with statistical analysis on trace elements (Chapter 22) – the making of potash glass in the Guangxi area. The fi ndings on potash glasses are certainly among the most interesting results of research. Since the discovery of the potash glass composition among glasses from southern China in the mid 1980s in the analyses by Shi Meiguang and those by Robert Brill, much more data is now available. However, the question of where the making of the potash glass originated is still unresolved, and is touched upon also by some of the other papers (see below, Brill ch.3,4, Lee 5). It is also found in Japan, Korea, Thailand, Vietnam, Indonesia, and southern India. Different compositional groups can be distinguished within the potash glass family (Lankton and Dussubieux 2006), here future research might further refi ne regional diff erentiation. Potash glass was very likely made in diff erent places, one of them was probably in southern China or northern Vietnam. The detection of thallium as a trace element in two potash glass ear spools of characteristic Chinese shape might indicate that some raw material – or possibly just the cobalt colourant – came from southwest China, where thallium deposits occur in Guizhou (Brill ch.5: 156-158). Whereas the Chinese-made glass objects are usually ornaments, a group of glass vessels made of potash glass, found in of Han period tombs in Guangxi, is of particular interest. The potash glasses and their possible connections with the routes of the maritime Silk Road will certainly remain an interesting fi eld for further studies.

In the last chapter 24, Gan Fuxi et al. present the earliest dated fi nd of glass imported from the West to Central China – eleven eye beads made of a soda-lime glass from a tomb in Xujialing, Henan, dated about 500 BCE. A few more such fi nds of Western glass are known from the tomb of Marquis Yi, Hubei, and two more tombs from Henan. Rooted firmly in the field of archaeometry, the volume presents altogether more than 40 tables with chemical compositions of glass found in China, derived from diff erent analysing methods. The emphasis is clearly on the early periods, from the origins of early Chinese glass in the mid-fi rst millenium BCE and its fi rst flourishing production in the Han period. The English edition will certainly be appreciated, and not only by specialists, as it facilitates access to recent results in a fascinating field of research. For the more generally interested reader a more careful proofread, in particular with regard to the rendering of geographical names, would have been helpful; these, however, are minor flaws. The volume will serve as a new compendium for studies on early Asian glasses, in the same way that, for almost two decades, the 1991 English publication of the Proceedings of the 1984 International Symposium on Glass, Beijing did.

Brigitte Borell
Independent scholar, Heidelberg, Germany
b_borell-seidel@hotmail.com

References

1. Fuxi, Gan. ed. 2005. Si chou zhi lu shang de gu dai bo li yan jiu: 2004 nian Wulumuqi Zhongguo bei fang gu bo li yan tao hui he 2005 nian Shanghai guo ji bo li kao gu yan tao hui lun wen ji (Study on ancient glass along the Silk Road: proceedings of 2004 Urumqi Symposium on Ancient Glass in Northern China and 2005 Shanghai International Workshop of Archaeology of Glass). Shanghai: Fudan University Press. ISBN 978 730 905 479-8. Proceedings of the XX International Congress on Glass, Kyoto, September 27-October 1. Tokyo 2005 (CD-ROM).

2. Lankton, J. and L.Dussubieux. Early glass in Asian maritime trade: a review and an interpretation of compositional analyses. Journal of Glass Studies 48, 2006 121-144.

3. Brill, R.H. and J.H.Martin. eds. 1991, Scientific Research in Early Chinese Glass. Corning: The Corning Museum of Glass.