Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-23T10:25:10.182Z Has data issue: false hasContentIssue false

The Reduction Welding Technique Used in Pre-Columbian Times: Evidences from a Silver Ring from Incallajta, Bolivia, Studied by Microscopy, SEM-EDX and PIXE

Published online by Cambridge University Press:  01 February 2011

Luis Torres Montes
Affiliation:
[email protected], Universidad Nacional Autónoma de México, Instituto de Investigaciones Antropológicas, Circ. Exterior s/n, Ciudad Universitaria, Mexico DF, 04510, Mexico
Jose Luis Ruvalcaba
Affiliation:
[email protected], Universidad Nacional Autónoma de México, Instituto de Fisica, Mexico DF, Mexico
Demetrio Mendoza Anaya
Affiliation:
[email protected], Instituto Nacional de Investigaciones Nucleares, Salazar, Edo. de Mexico, Mexico
Maria de los Angeles Muñoz Collazo
Affiliation:
[email protected], Universidad Mayor de San Simon, Museo Arqueológico, Cochabamba, Bolivia
Francisca Franco Velázquez
Affiliation:
[email protected], Universidad Autónoma Metropolitana-Azcapotzalco, Depto. de Materiales, Mexico DF, Mexico
Francisco Sandoval Pérez
Affiliation:
[email protected], Universidad Autónoma Metropolitana-Azcapotzalco, Depto. de Materiales, Mexico DF, Mexico
Get access

Abstract

A pre-Columbian silver ring from Incallajta, Bolivia, recovered from an archaeological excavation is composed of a thin sheet of silver bent to form the ring. Two small wires in the shape of the infinity sign are joined to the surface of the ring. Four green stone beads were laid inside the four cavities formed by the wires. Energy dispersive spectroscopy (EDX) and Particle Induced X-rays Emission (PIXE) analyses of the beads proved that they were turquoise. Examination with a stereoscopic binocular microscope indicated that the two wires could have been soldered to the ring by reduction welding, because copper corrosion products were found in the interface of the welding, similar to those seen on two modern silver objects from Indonesia, decorated with granulation. Since reduction welding is a technique not reported before in pre-Columbian metallurgy, further analyses were carried out to prove that it was used here. Thus, the ring was analyzed with Scanning Electron Microscopy (SEM-EDX) and external beam PIXE, showing with certainty that the copper content in the area of the welding was higher than in any other part of the ring, with increasing copper amounts towards the center of the weld.

Type
Research Article
Copyright
Copyright © Materials Research Society 2008

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Collazo, M.A. Muñoz, 2006. Gestión Participativa del Patrimonio: Un caso Boliviano, Cuadernos de Antropología y Patrimonio Cultural 4. INAH-CONACULTA, Mexico, 3- 47.Google Scholar
2. Respaldiza, M. A. & Gómez-Camacho, J. (eds.), 1997. Applications of Ion Beam Analysis Techniques to Arts and Archaeometry, Universidad de Sevilla, Sevilla.Google Scholar
3. Sil, J.L. Ruvalcaba. 2005. Analysis of Pre-Hispanic Items from Ancient America in X-rays in Archaeology, Uda, M., Demortier, G., Nakai, I., coord, , Springer, Dordrecht, 123149.Google Scholar
4. Peso, Ch.C. Di, Rinaldo, J. B. and Fenner, G. J., 1974. Casas Grandes. A Fallen Trading Center of the Gran Chichimeca. Vol. 7 Stone and Metals. The Amerind Foundation Inc., Northland Press, 500532.Google Scholar
5. Gettens, R.J., 1963. Mineral Alteration Products in Ancient Metal Objects in Recent Advances in Conservation, Thomson, G., Editor, Butterworths, London, 8992.Google Scholar
6. Nestler, G., Formigli, E., 2004. Granulazione Etrusca, Un'antica tecnica orafa, Nuova Immagine Ed., Siena.Google Scholar
7. Beck, L., Bosonnet, S., Réveillon, S., Eliot, D., Pilon, F., 2004. Nuclear Instruments and Methods B 226, 153162.Google Scholar
8. Massalsi, T.B., 1992. Binary alloy phase diagrams, ASM International, Ohio, 29.Google Scholar
9. Sil, J.L. Ruvalcaba, Bucio, L., Marín, M.E. & Velázquez, A., 2005. Estudio por XRD y haces de iones de teselas de un disco de turquesas del Templo Mayor de Tenochtitlán in La Ciencia de Materiales y su Impacto en la Arqueología. Vol II, Academia Mexicana de Ciencia de Materiales A.C., Mendoza, D., Arenas, J. y Rodríguez, V. coord., Ed. Lagares, México, 95-11.Google Scholar