Characterization and Conservation of Bronze Coins Excavated from Tell Timai, El Sembelawen, Daqahleya, Egypt

Document Type : Original Article

Authors

1 Conservator at the Ministry of Antiquities

2 Polymer Dept., National research centre

3 Conservation department, Faculty of Archaeology, Cairo University

Abstract

Several archaeological coins were discovered in Tell Timai, Elsembelawen, Daqahleya. They were heavily corroded and in a bad state of preservation. Different corrosion products mixed with soil encrustation totally obscured the surface. The present paper aims to identify the morphology and composition of the alloy and corrosion products, perform a condition assessment and determine the best methods for treatment. Therefore, an analytical and characterization study on coin samples was carried out using X-ray diffraction analysis and portable X-ray fluorescence to understand the nature and composition of the alloy and patina. The results indicated the deterioration of the coins. X-ray diffraction analysis showed that the corrosion layers were mostly composed of chlorides, sulfates, and carbonates with some soil residues of gypsum and other compounds. X-ray fluorescence results showed that the coins consisted of ternary alloy [copper, tin, and lead ].The composition of the coins indicated that several coins were high-leaded bronze, except one made from leaded copper. Finally, the results obtained help choose the best treatment and conservation methods. The conservation of the coins required removing the soiled deposits, encrustations, and corrosion layers covering the coins completely while preserving their integrity.

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Volume 65, Issue 13 - Serial Number 13
Special Issue: Chemistry and Global Challenges
December 2022
  • Receive Date: 16 August 2022
  • Revise Date: 17 October 2022
  • Accept Date: 09 November 2022
  • First Publish Date: 09 November 2022