Skip to main content Accessibility help

Effects of Long-Term Aging in Arsenical Copper Alloys

  • Filipa Pereira (a1) (a2), Rui J. C. Silva (a1), António M. Monge Soares (a2) (a3), Maria F. Araújo (a2), Maria J. Oliveira (a4), Rui M. S. Martins (a1) (a5) (a6) and Norberth Schell (a7)...


Archaeological materials present unique records on natural processes allowing the study of long-term material behaviors such as structural modifications and degradation mechanisms. The present work is focused on the chemical and microstructural characterization of four prehistoric arsenical copper artifacts. These artifacts were characterized by micro-energy dispersive X-ray fluorescence spectrometry, optical microscopy, scanning electron microscopy with X-ray microanalysis, micro-X-ray diffraction and synchrotron radiation micro-X-ray diffraction. Cu3As is the expected intermetallic arsenide in arsenical copper alloys, reported in the literature as exhibiting a hexagonal crystallographic structure. However, a cubic Cu3As phase was identified by X-ray diffraction in all of our analyzed archaeological artifacts, while the hexagonal Cu3As phase was clearly identified only in the artifact with higher arsenic content. Occurrence of the cubic arsenide in these particular objects, suggests that it was precipitated due to long-term aging at room temperature, which points to the need of a redefinition of the Cu-As equilibrium phase constitution. These results highlight the importance of understanding the impact of structural aging for the assessment of original properties of archaeological arsenical copper artifacts, such as hardness or color.


Corresponding author

* Corresponding author.


Hide All
Bengough, G.D. & Hill, B.P. (1910). The properties and constitution of copper-arsenic alloys. J Inst Met 3, 3471.
Budd, P. (1991). Eneolithic arsenical copper: heat treatment and the metallographic interpretation of manufacturing processes. In Proceedings of Archaeometry (vol. 90 Pernika, E. & Wagner, G.A. (Eds.), pp. 3544). Basel: Birkhäuser.
Budd, P. & Ottaway, B.S. (1995). Eneolithic arsenical copper: chance or choice? In International Symposium, Ancient Mining and Metallurgy in Southeast Europe, Jovanovic, B. (Ed.), pp. 95102. Belgrade: Archaeological Institute.
Dewalens, J., Heerman, L. & Simaeys, L.V. (1951). The codeposition of copper and arsenic from H2SO4‐CuSO4 ‐ As2O3 solutions, electrochemical formation of copper arsenides. J Electrochem Soc 122(4), 477482.
Giumlia-Mair, A. (2008). The metal of the moon goddess. Surface Engineering 24(2), 110117.
Hammersley, A.P., Svensson, S.O., Hanfland, M., Fitch, A.N. & Häusermann, D. (1996). Two-dimensional detector software: from real detector to idealised image or two-theta scan. High Pressure Res 14, 235248.
Hawkins, D.T. (1973). Metals Handbook, Metallography, Structures and Phase Diagrams, 8th ed., vol. 8 Materials Park, OH: American Society for Metals. 265pp.
Heyding, R.D. & Despault, G.J.G. (1960). The copper/arsenic system and the copper arsenide minerals. Can J Chem 38(12), 24772481.
Iglesias, J.E. & Nowacki, W. (1977). Refinement of the crystal structure of α domeykite, struture related to the A15 type. Z Kristallogr 145, 334345.
McKerrell, H. & Tylecote, R.F. (1972). The working of copper-arsenic alloys in the Early Bronze Age and the effect on the determination of provenance. Proc Prehist Soc 38, 209218.
Naud, J. & Priest, P. (1972). Contributions to the study of the copper-arsenic system. Mater Res Bull 7, 783792 (in French).
Northover, J.P. (1989). Properties and use of arsenic-copper alloys. In Old World Archaeometallurgy (Der Anschnitt, Beiheft 7, Hauptmann, A., Pernicka, E. & Wagner, G.A. (Eds.), pp. 111118). Bochum: Deutsches Bergbaumuseum, B.
Okamoto, H. (1991). Revaluation of thermodynamic models for phase diagram. J Phase Equil 12, 623643.
Padera, K. (1952). Revision of the domeykite-algodonite group. Acad Tcheque Sci Bull Int Classe Sci, Math, Nat, Med 52, 5368.
Pei, B., Björkman, B., Jansson, B. & Sundman, B. (1994). Thermodynamic assessment of the Cu-As system using an ionic two-sublattice model for the liquid phase. Z Kristallogr 85(3), 178184.
Pereira, F., Silva, R.J.C., Soares, A.M.M. & Araújo, M.F. (2013). The role of arsenic in Chalcolithic copper artefacts – insights from Vila Nova de São Pedro (Portugal). J Archaeol Sci 40, 20452056.
Predel, B. (2006). As-Cu (Arsenic – Copper), Ac-Ag… Au-Zr, 12A, Subvolume IV/5A In Phase Equilibria, Crystallographic and Thermodynamic Data of Binary Alloys, Madelung, O. (Ed.), 14. Landolt-Börnstein, Berlin: Springer.
Ravič, I.G. & Ryndina, N.V. (1984). Izučenie svojstv I mikrostrukturny splavov med’-myš’jak v svjazi s ich ispol’zovaniem v drevnosti. (On the investigation of the properties and microstructure of the copper-arsenic alloys in conjunction with their use in antiquity) Chudožestvennoe nasledie (Art Heritage) 39(9), 114124.
Schell, N., King, A., Beckmann, F., Fischer, T., Müller, M. & Schreyer, A. (2014). The high energy materials science beamline (HEMS) at PETRA III. Mater Sci Forum 772, 5761.
Scott, D.A. (1991). The microstructure of ancient metals. In Metallography and Microstructure of Ancient and Historic Metals, Averkieff, I. (Ed.), pp. 2. Oxford University Press, USA: The Getty Conservation Institute.
Skinner, B.J. & Luce, F.D. (1971). Stabilities and compositions of α-domeykite and algodonite. Econ Geol 66, 133139.
Smithells, C.J. (1962). Metal Reference Book, 3rd ed., vol. 1 London, UK: Butterworths.
Soares, A.M.M. (2005). A metalurgia de Vila Nova de São Pedro. Algumas reflexões. In Construindo a memória (As colecções do Museu Arqueológico do Carmo, Arnaud, M. & Fernandes, C.V. (Eds.), pp. 179188). Lisboa: Associação dos Arqueólogos Portugueses, PT.
Subramanian, P.R. & Laughlin, D.E. (1998). The As-Cu (Arsenic-Copper) system. Bull Alloy Phase Diagr 9(5), 605617.
Teppo, O. & Taskinen, P. (1991). An assessment of the thermodynamic properties of arsenic-copper alloys. Scand J Metall 20, 141148.
Valério, P., Araújo, M.F. & Canha, A. (2007). EDXRF and micro-EDXRF studies of Late Bronze Age metallurgical productions from Canedotes (Portugal). Nucl Instrum Meth B 263, 477482.
Valério, P., Soares, A.M.M., Maria Araújo, M.F., Silva, R.J.C. & Baptista, L. (2015). Middle bronze age arsenical copper alloys in southern Portugal. Archaeometry, doi:10.1111/arcm.12212 (in press).
Valério, P., Soares, A.M.M., Maria Araújo, M.F., Silva, R.J.C., Porfírio, E. & Serra, M. (2014). Arsenical copper and bronze in Middle Bronze Age burial sites of southern Portugal: the first bronzes in Southwestern Iberia. J Archaeo Sci 42, 6880.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

Microscopy and Microanalysis
  • ISSN: 1431-9276
  • EISSN: 1435-8115
  • URL: /core/journals/microscopy-and-microanalysis
Please enter your name
Please enter a valid email address
Who would you like to send this to? *



Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed