Statistical Study of the Achaemenid, Parthian and Sassanid Silver Coins Using Elemental Analysis by PIXE Technique

In this study, 27 Achaemenid coins, 62 Parthian coins, 66 Sassanid coins, have been analyzed. The Achaemenid coins as well as 20 Parthian coins belong to the National Museum of Iran and the other 42 Parthian coins are kept in Tamashagah-e Pool Museum. Sasanid coins belong to private collectors. Using PIXE analysis, the element concentrations of the coins were measured. By using statistical analysis on the concentration of the elements, the samples were analyzed using factor analysis method. Statistical analysis shows that the coins belonging to the Achaemenid and Sassanid periods can be identified and separated based on the changes of Cu/Ag, Pb/Ag and Au/Ag ratios. In particular the relative change in Cu/Ag ratio in the Achaemenid period is very low, whereas it is high for the Parthian Coins.