The Becin hoard – Analysis of the ancient silver coins

During the archaeological work in summer 2000 a spectacular hoard of silver coins could be excavated at the medieval site Becin, next to Ephesos / Turkey. This hoard, whose total weight amounted to approximately 30 kg, includes about 60.000 Islamic coins as well as 830 European coins and represents the largest finding of coins ever made in Turkey. One of the most outstanding features of the Becin hoard is the fact that almost all mint places recorded for the Ottoman Empire and all rulers of the second half of the 16th century up to the beginning of the 17th century are represented in this treasure. Thus, the numismatic evaluation and the material analysis of the coins will provide a general insight in the monetary and economic history of the Ottoman Empire in this time.
In a first step of the investigations a collection of 450 samples was analyzed quantitatively. Photon, electron and proton induced X-ray analysis provide complementary information on the chemical composition of the coins. Using EDXRF, the content of both the major constituent Ag and the minor elements Cu and Pb were determined. The advantage of SEM/EDX is the ability to analyze small areas of the cross-sections. Finally, PIXE measurements were carried out in order to characterize also the trace elements, like Au, Bi, Fe, Ni. The initial results show on the one hand an arrangement in different groups of coins concerning their chemical composition. On the other hand the findings illustrate frequent devaluations in the fineness of the silver coins described in the Ottoman written sources.