Archaeometallurgical Characterization and Condition Assessment of Ancient Roman Coins from Egypt | ||
| Shedet | ||
| Article 11, Volume 8, Issue 8, 2021, Pages 149-167 PDF (2.44 M) | ||
| Document Type: research articles | ||
| DOI: 10.21608/shedet.2021.82804.1067 | ||
| Authors | ||
| Hasnaa Ahmed* 1; Gamal Mahgoub2; Saleh Mohamed2; Abdelrazek Elnaggar3 | ||
| 1Heritage Science Mobile Lab, Faculty of Archaeology, Fayoum University, Fayoum, Egypt | ||
| 2Conservation department, Faculty of Archaeology, Fayoum University, Fayoum, Egypt | ||
| 3Heritage Science Mobile Lab, Faculty of Archaeology, Fayoum University, Fayoum, Egypt Conservation department, Faculty of Archaeology, Fayoum University, Fayoum, Egypt | ||
| Abstract | ||
| This paper presents scientific investigations of three ancient Roman coins excavated from Al Sheikh Zuweid, Sinai city in 2002. A punch of examination and analytical techniques consists of stereo microscope, optical microscope, scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) and X-ray diffraction (XRD) are used to study the morphological characteristics of the coins patina, to identify the chemical composition of the metallic core, to determine the corrosion products and to understand the corrosion mechanism. The results indicate that copper is the major element of the three coins with small proportion of silver and tin. The presence of tin in the composition of two coins refers to bronze alloy. The identification of the exact corrosion products is determined by XRD analysis. The results reveal that the corrosion products consist mainly of cuprite and tenorite. Also, the results indicate that the coins were buried in a soil rich in chloride ions due to the presence of copper hydroxychlorides such as paratacamite and atacamite. Metallographic investigation is used to reveal the coins manufacture and identify spatial distribution of the alloy components and phases. Also, metallographic investigation indicates pitting corrosion resulted from the attack of chloride and the occurrence of a “bronze disease” phenomenon. The results of this study can provide valuable information that helping in conservation and preservation of the archaeological coins. | ||
| Keywords | ||
| coins; copper-based alloy; archaeometallurgy; SEM-EDX; XRD | ||
| References | ||
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BIBLIOGRAPHY
1- Allen, Ch., A systematic study of the corrosion layers on excavated coins from varying historical periods, PhD diss., University of Huddersfield, 2016.
2- Al-Zahrani, A& Ghoniem, M., ‘A characterization of coins from the najran hoard, saudi arabia, prior to conservation’, in: International Journal of Conservation Science3, no. 3 (2012), 150-151.
3- Bresle, Å& Saers, J& Arrhenius, B., Studies in pitting corrosion on archaeological bronzes, 1983.
4- Brown, B. F& Pourbaix, M& Kruger, J& Goodway, M& Chase, W. Th& Burnett, H. C., ‘Corrosion and metal artifacts: a dialogue between conservators and archaeologists and corrosion scientists’ in: US Department of Commerce, National Bureau of Standards 479 (1977): 1-4.
5- Bryan, B., "Copper Alloy Objects Suspected of Bronze Disease: The Burrell ‘Bronzes’." In: Studies in Archaeological Conservation, (2020): 115-123.
6- Cruz, J& Manso, M& Corregidor, V& Silva, R.J.C& Figueiredo, E& Carvalho, M.L& Alves, L.C., ‘Surface analysis of corroded XV–XVI century copper coins by μ-XRF and μ-PIXE/μ-EBS self-consistent analysis,’ in: Materials Characterization161 (2020), 110170.
7- Demidova, E., Archaeometallurgical characterisation of ancient Roman bronze coins, Master's thesis, Universidade de Évora, 2016, 16-71.
8- Di Fazio, M&Felici, A. C& Catalli, F& De Vito, C., ‘Microstructure and chemical composition of Roman orichalcum coins emitted after the monetary reform of Augustus (23 BC)’ in: Scientific reports 9, no. 1 (2019): 1-11.
9- Ghoniem, M., ‘The characterization of a corroded Egyptian bronze statue and a study of the degradation phenomena’, in: International Journal of Conservation Science 2, no. 2 (2011), 103-104.
10- MacLeod, I., ‘Bronze disease: an electrochemical explanation’, in: ICCM Bulletin 7, no. 1 (1981), 16-26.
11- Mata, A& Carneiro, A& Neto, M& Proença, L& Salta, M& Mendonça, M. H& Fonseca, I.T., ‘Characterisation of five coins from the archaeological heritage of Portugal’in: Journal of Solid State Electrochemistry 14, no. 3 (2010), 495-503.
12- Mircea,O& Sandu, I& Vasilache, V& Sandu, I., ‘A study on the deterioration and degradation of metallic archaeological artifacts’, in: International Journal of Conservation Science 3, no. 3 (2012), 180.
13- Nord, A.G& Mattsson, E& Tronner, K., ‘Factors influencing the long-term corrosion of bronze artifacts in soil’ in: Protection of metals 41, no. 4 (2005), 309-316.
14- Oudbashi, O., ‘A methodological approach to estimate soil corrosivity for archaeological copper alloy artifacts, in: Heritage Science6, no. 1 (2018), 1-15.
15- Pedeferri, P., ‘Pitting Corrosion’, Corrosion science and engineering. (2018), 207-230.
16- Plattner, S.H& Campanella, L& Colacicchi, O& Ferretti, M., The Corrosion of Archaeological Copper Alloys. The case study of a coin hoard from the Tenuta Radicicoli-del Bene, Rome. 2006.
17- Quaranta, M., On the degradation mechanisms under the influence of pedological factors through the study of archeological bronze patina, Master's thesis, 2009.
18- Reale, R& Plattner, S. H& Guida, G& Sammartino, M&Visco, G., ‘Ancient coins: cluster analysis applied to find a correlation between corrosion process and burial soil characteristics’, in: Chemistry Central Journal 6, no. 2 (2012): 1-9.
19- Roberge, P. R., Handbook of corrosion engineering, Library of Congress Cataloging-in-Publication Data, (2000): 142.
20- Salem, Y& Mohamed, E., ‘The role of archaeometallurgical characterization of ancient coins in forgery detection’, in: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 461, (2019), 247-255.
21- Sandu, I. G& Mircea, O& Vasilache, V& Sandu, I., ‘Influence of archaeological environment factors in alteration processes of copper alloy artifacts’, in: Microscopy Research and Technique 75, no. 12 (2012), 1646-1652.
22- Sandu, I& Mircea, O& Sandu, I. G& Vasilache, V., ‘The liesegang effect on ancient bronze items discovered in Romania’, in: International Journal of Conservation Science, (2013), 573.
23- Schweizer, F., ‘Bronze objects from lake sites: from patina to" biography’, In: Ancient and historic metals: conservation and scientific research: proceedings of a symposium organized by the J. Paul Getty Museum and the Getty Conservation Institute, (1991), 33-50.
24- Scott, D. A., Copper and bronze in art: corrosion, colorants, conservation, Getty publications, 2002.
25- –––––––––––., Metallography and microstructure in ancient and historic metals, Getty publications, 1992.
26- –––––––––––., ‘Periodic corrosion phenomena in bronze antiquities’, in: Studies in Conservation 30, no. 2 (1985): 49-57.
27- Scott, D. A& Podany, J& Considine, B (eds.), "Ancient & historic metals: conservation and scientific research." Getty Publications (1994).
28- Van Ham-Meert, A& Rademakers, F.W& Gyselen, R& Overlaet, B& Degryse, P& Claeys, P., ‘Sasanian copper and billon coins from the collections of the Royal Museums of Art and History, Brussels, Belgium—insights using semi-quantitative analysis by μXRF,’ in: Archaeological and Anthropological Sciences 12, no. 10 (2020): 1-21.
29- Verma, P& Lal, G& Singh, M., ‘Microstructural characterization of early Twentieth-Century British period Indian copper coins.’ X-Ray Spectrometry, (2021), 1-9.
30- Vijayakumar, M& Ganorkar, M.C.& Rao, V. P& Gayathri, P., ‘A study of Vishnukundin coins’, in: Bulletin of Materials Science 9, no. 2 (1987), 137-147. | ||
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