Abstract
By means of the combined use of surface and micro-analytical techniques the surface chemical composition of ancient coins and some aspects of their manufacturing techniques and of degradation mechanisms have been elucidated. Two case histories are described concerning silver Roman Republican coins and some coins plated with thin films of silver and gold. In particular, the coinage methods, the silvering and gilding techniques and the origin of the embrittlement of these selected Roman coins have been studied by means of the combined use of selected-area X-ray photoelectron spectroscopy (SA-XPS) and scanning electron microscopy and energy-dispersive spectrometry (SEM+EDS). This innovative approach has been utilised in order to gain further insight into the microchemical structure of the external regions of the coins as well as of the bulk features. The results show the use of mercury to coat a copper or silver core with a thin film of precious metals that could be considered the most important advance in the technology of gilding to be made in antiquity. Furthermore, the microchemical investigation of brittle Roman silver coins has allowed us to identify the origin of this troublesome problem. The microchemical results indicate that brittleness is induced by the presence of a low amount of lead that is retained in supersaturated solution when the cast blank was produced. This latter element segregates at the grain boundaries during the coin production and the subsequent long-term ageing at room temperature, thus inducing the alloy fracturing along the weakened grain boundaries.
Similar content being viewed by others
References
G.M. Ingo, G. Bultrini, E. Lo Piccolo, L.-I. Manfredi: Archaeometry 39, 59 (1997)
D.A. Scott: J. Am. Inst. Conserv. 29, 193 (1990)
D.A. Scott: Metallography and Microstructure of Ancient and Historic Metals (The Getty Conservation Institute, Paul Getty Museum, Malibu, CA 1991)
G.M. Ingo, G. Bultrini, D. Attanasio: Archaeometry 43, 529 (2001)
G.M. Ingo, L.-I. Manfredi, G. Bultrini, G. Chiozzini, S. Caroli: in Proc. XII Int. Numismatischer Kongr., ed. by B. Kluge, B. Weisser (Staatliche Museen zu Berlin, Berlin 2000) p. 306
P.A. Lins, W.A. Oddy: J. Archaeolog. Sci. 2, 365 (1975)
A. Oddy: ‘Gilding of Metals in the Old World’. In: Metal Plating and Patination, ed. by S. La Niece, P.T. Craddock (Butterworth-Heinemann, Oxford 1993)
K. Anheuser: Bull. Met. Mus. 26, 48 (1996)
M.H. Crawford: The Roman Republican Coinage (Cambridge University Press 1975) p. 569
R.J.H. Wanhill, J.P.H.M. Steijart, R. Leenheer, J.F.W. Koens: Archaeometry 40, 123 (1998)
I.G. Ravich: in Proc. Tenth Trienn. Meet. Int. Council of Museums Committee for Conservation, Vol. II (Reinhold Publishing Co., Washington, DC 1993) p. 792
F.C. Thompson, A.K. Chatterjee: Stud. Conserv. 1, 155 (1954)
L. Addicks: Silver in Industry (Reinhold, New York 1940)
A. Butts: Copper, the Science and Technology of the Metal. Its Alloys and Compounds (Am. Chem. Soc. Monogr. Ser. 12) (Reinhold Publishing Co., New York 1954) p. 702
D. Ott: Handbook on Casting and Other Defects in Gold Jewellery Manufacture (World Gold Council, Industrial Division, London 1997)
Author information
Authors and Affiliations
Corresponding author
Additional information
PACS
68.55.Jk; 68.35.Dv; 68.37.Hk; 68.55.Nq; 81.05.Bx
Rights and permissions
About this article
Cite this article
Ingo, G., Angelini, E., de Caro, T. et al. Combined use of surface and micro-analytical techniques for the study of ancient coins. Appl. Phys. A 79, 171–176 (2004). https://doi.org/10.1007/s00339-004-2510-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00339-004-2510-8