Physico-Chemical and Numismatic Study of Moroccan Silver Coins from the Almohad Dynasty (XII to XIII Century)

Abstract

This study obtains information on the constitution of the coinage alloy and the elements of contamination on the surface of archaeological objects. Thus, this work consists of physico-chemical characterization of old coins by MEB coupled with the EDS of 36 Almohade’s dynasty Islamic coins (XII-XIII century). In addition to the physico-chemical analysis of which the data are treated using tools statistical mathematics with the help of software SPSS, the parts being studied were the subject of a historical and numismatic analysis. The results of this work conclude that these silver coins contain: Ag, C, Cu, Mg, O, Si, Al, Au, Cl, Sr, S, Pb and Fe. The analysis also made it possible to dissociate the elements belonging to the original alloy from those, which are not. So we can say that the elements that come primarily from silver-bearing alloys of origin are Ag, C, Cu, Mg, Au, S, Pb and Fe. The other elements are due to different phenomena (corrosion, contamination etc). Let us recall, finally, that in most cases, we notice that a good amount of numismatic, historical, archaeological and mining data is confirmed by the results of the physico-chemical characterization. The novelty of this work lies in the fact that the results can, among other things, be used for improving the methods and techniques of conservation and restoration of these archaeological objects and their development.