Copper granulation: scientific analysis on the ornaments from the coronet of Lady Pei of the early Tang Dynasty (618–712 A.D.) in Xi’an, Shaanxi, China

  • Panpan Tan
  • Junchang YangEmail author
  • Yaozheng Zheng
  • Junkai Yang
Original Paper


Granulation is an ancient decorative technique for metalwork. Granulated finds are most commonly made of precious metals such as gold and silver, while copper granulation is very rare, and it has even been claimed that it was not employed in antiquity. This paper presents a scientific analysis of granulated copper ornaments from a gilded coronet belonging to Lady Pei (d. 691 A.D.) that was uncovered from an early Tang Dynasty tomb in Xi’an, China. In addition to common methods such as X-ray radiography, metallographic investigation, and scanning electron microscope observation including energy dispersive spectroscopy to examine the microstructure and elemental composition, X-ray micro-computed tomography was used to investigate the internal microstructure of granulation for the first time. The results affirm that copper granulation technique was used to decorate the coronet. Notably, further study shows that the copper granules and wires were joined to the substrate with silver–copper alloy hard solder and arrives at an estimate of the alloy mixing ratio. These observations are used to infer the manufacturing process: copper granules of two sizes were first brazed to the wires and substrate, and then mercury was used to gild the whole ornament. This work provides new insights for the study of ancient granulation techniques, especially through the scientific study of the very rare examples of copper work.


Granulation Copper Silver–copper alloy solder Mercury gilding Tang Dynasty μ-CT 



We would like to thank the Xi’an Institute of Conservation and Archaeology on Cultural Heritage for the samples. The authors are grateful to Ms. Xiaojuan Dang, Ms. Juan Ji, and Mr. Jiankai Xiang from Shaanxi Institute for the Preservation of Cultural Heritage, for the support and help on the metallographic investigation, SEM-EDS, and X-ray radiography. Special thanks go to Dr. Yan Liu, Ms. Yingzi Zhangsun, and Ms. Yuanyuan Zhang for suggestions on the manuscript.

Funding information

The study was financially supported by the National Natural Science Foundation of China (51674206) and Science and Technology Project of Inner Mongolia Autonomous Region (JH20180250).


  1. Ashkenazi D, Gitler H, Stern A, Tal O (2017) Metallurgical investigation on fourth century BCE silver jewellery of two hoards from Samaria. Sci Rep 7:1–14. CrossRefGoogle Scholar
  2. Bernardini F, Sibilia E, Kasztovszky Z, Boscutti F, de Min A, Lenaz D, Turco G, Micheli R, Tuniz C, Montagnari Kokelj M (2018) Evidence of open-air late prehistoric occupation in the Trieste area (north-eastern Italy): dating, 3D clay plaster characterization and obsidian provenancing. Archaeol Anthropol Sci 10:1933–1943. CrossRefGoogle Scholar
  3. Bettuzzi M, Casali F, Morigi MP, Brancaccio R, Carson D, Chiari G, Maish J (2015) Computed tomography of a medium size Roman bronze statue of Cupid. Appl Phys A 118:1161–1169. CrossRefGoogle Scholar
  4. Dang X, Yang J, Li R, Shu J (2018) Research on materials and craftmanships of hairpins unearthed from the tomb of Empress Xiao of Emperor Sui Yang. Wenwu Baohu yu Kaogu Kexue (Sciences of Conservation and Archaeology) 30:1–10 (in Chinese)Google Scholar
  5. Ding Z, Zhou Y, Wu L (2017) X-CT computed tomography studies on the manufacturing techniques of Zi Zhong Jiang Pan. Wenwu Baohu yu Kaogu Kexue (Sciences of Conservation and Archaeology) 29:12–25 (in Chinese)Google Scholar
  6. Hackens T, Winkes R (eds) (1983) Gold jewelry: craft, style and meaning from Mycenae to Constantinopolis. Institut Superieur d’Archaeologie et d’Histoire De l’art, College Erasme, Louvain-la-NeuveGoogle Scholar
  7. Han W, Wang Z, Jin X, Cao W, Ren Z, Huai J, Fu S (1988) The excavation of the hoard of the Famen Temple of the Tang Dynasty in Baoji. Wenwu (Cultural Relics) (10):1–28, 97–105 (in Chinese)Google Scholar
  8. Higgins RA (1962) Decorative processes. Greek and Roman jewellery. Methunen & Co Ltd., London, pp 19–30Google Scholar
  9. Huang W, Wu X, Chen J, Wang H (2009) A study of gold tube ornaments excavated from the Majiayuan cemetery in Zhangjiachuan. Wenwu (Cultural Relics) (10):78–84 (in Chinese)Google Scholar
  10. Kang J, Heng Y, Wang X, Yan H (2017) Scientific analysis of copper loop from M36 in printing and dyeing factory in Sanmenxia, Henan. Wenwu Chunqiu (Spring and Autumn of Cultural Relics) (4):53–58 (in Chinese)Google Scholar
  11. Liu X (1975) Personal adornment. Old book of Tang. Vol. 45. Zhonghua Book Company, Shanghai, pp 1929–1960 (in Chinese)Google Scholar
  12. Maryon H (1949) Metal working in the ancient world. Am J Archaeol 53:93–125. CrossRefGoogle Scholar
  13. Maryon H, Plenderleith HJ (1954) Fine metal working. In: Singer C, Holmyard EJ, Hall AR (eds) A history of technology. Vol. 1, From early times to the fall of ancient empires. O.U.P., New York, pp 623–662Google Scholar
  14. Maxwell-Hyslop KR (1977) Sources of Sumerian gold: the Ur goldwork from the Brotherton Library, university of Leeds. A preliminary report. Iraq 39:83–86. CrossRefGoogle Scholar
  15. Mortazavi M, Naghavi S, Khanjari R, Agha-Aligol D (2017) Metallurgical study on some Sasanian silver coins in Sistan Museum. Archaeol Anthropol Sci 10:1831–1840. CrossRefGoogle Scholar
  16. Natuniewicz-Sekuła M (2017) The craft of the goldsmith in Wielbark Culture in the light of the finds from the cemetery at Weklice, Elbląg Commune and other Necropolis of Roman period from Elbląg Heights. Technological studies of selected aspects. Sprawozdania Archeologiczne 69:185–233. CrossRefGoogle Scholar
  17. Nestler G, Fomigli E (2010) Etruscan granulation: an ancient art of goldsmithing. Brynmorgen Press, Hong Kong (in English)Google Scholar
  18. Qi D (2005) Brief discussion on the copper wares of the Tang Dynasty. Wenbo (Relics and Museolgy):33–37 (in Chinese)Google Scholar
  19. Qiang T (ed) (2007) Shexianjiance. China Human Resources & Social Security Publishing Group Co.,Ltd, Beijing (in Chinese)Google Scholar
  20. Ro J, Yu H (2016) A study of metalworking techniques seen in the gold buckle from Seogam-ri tomb No. 9. Conserv Sci Museum 17:1–16 (in Korean)Google Scholar
  21. Rossi M, Casali F, Romani D, Bondioli L, Macchiarelli R, Rook L (2004) MicroCT scan in paleobiology: application to the study of dental tissues. Nucl Inst Methods Phys Res B 213:747–750CrossRefGoogle Scholar
  22. Schlosser S, Reinecke A, Schwab R, Pernicka E, Sonetra S, Laychour V (2012) Early Cambodian gold and silver from Prohear: composition, trace elements and gilding. J Archaeol Sci 39:2877–2887. CrossRefGoogle Scholar
  23. Scott DA (1991) Appendix: phase diagrams. In: Averkieff I (ed) Metallography and microstructure of ancient and historic metals. Tien Wah Press Ltd., Singapore, p 129Google Scholar
  24. Scrivano S, Ruberto C, Gómez-Tubío B, Mazzinghi A, Ortega-Feliu I, Ager FJ, Laclavetine K, Giuntini L, Respaldiza MA (2017) In-situ non-destructive analysis of Etruscan gold jewels with the micro-XRF transportable spectrometer from CNA. J Archaeol Sci Rep 16:185–193. Google Scholar
  25. Tan P, Ji J, Yang J, Wang J, Ma J (2016) Scientific analysis of gold and silver artifacts from M1 of Xigou site in Balikun Autonomous County, Hami Prefecture, Xinjiang Wenwu (Cultural Relics) (5):85–91 (in Chinese)Google Scholar
  26. Wang S (ed) (2000) Wanshoushan Guangchusi Ciqiku Tongzuo, Xizuo Zeli, Neigongyouzuo Xianxingzeli. Qingdaijiangzuozelihuibian. Vol. 1, vol 26. Elephant press, Henan, pp 1181–1218 (in Chinese)Google Scholar
  27. Wolters J (1981) The ancient craft of granulation. Gold Bull 14:119–129CrossRefGoogle Scholar
  28. Xi’an Institute of Conservation and Archaeology on Cultural Heritage (ed) (2011) Xi’an Wenwu Jinghua: gold and silver wares. World Publishing Corporation, Xi’anGoogle Scholar
  29. Yang J, Dang X, Bai K (2014a) Gold granulation of the Tang Dynasty: the discoveries, microscopic observation and the materials nature. Wenbo (Relics and Museolgy) (4):79–84 (in Chinese)Google Scholar
  30. Yang J, Feng J, Wang L, Shi H, Zheng X, Pan Y, Zhao Z, Kou X, Dang X, Zhang X (2014b) The excavation of the tomb of the couple of Yan Shiwei, the Sima of Tai Prefecture of the Tang Dynasty at Majiagou in Xi’an. Wenwu (Cultural Relics) (10):25–48 (in Chinese)Google Scholar
  31. Zhao K (1985) The excavation of the hoard of the Qingshan Temple in Xi’an. Wenbo (Relics and Museolgy) (5):12–37, 99–100 (in Chinese)Google Scholar
  32. Zheng F (2015) Zuo Zhaojingjing. In: Han Y, Xu C (eds) Jinginglingchiyizhu. Vol. 4. Shanghai Guji Press, Shanghai, pp 276–296 (in Chinese)Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Panpan Tan
    • 1
  • Junchang Yang
    • 2
    Email author
  • Yaozheng Zheng
    • 1
  • Junkai Yang
    • 3
  1. 1.State Key Laboratory of Solidification Processing, Center for Nano Energy Materials, School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’anChina
  2. 2.Institute of Culture and HeritageNorthwestern Polytechnical UniversityXi’anChina
  3. 3.Xi’an Institute of Conservation and Archaeology on Cultural HeritageXi’anChina

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