Multi-elemental analysis of colonial and post-colonial Nigerian coins by Proton Induced X-ray Emission (PIXE) spectrometry

Abstract

The investigation of old and new coins from different countries in the world has generated a growing interest among numismatic and archaeological researchers. The challenge is to explain the large diversification of these coins, to determine the differences in composition, weight and physical aspects. A non-destructive physical method of ion beam analysis; PIXE was employed to investigate elemental properties of colonial and post-colonial Nigerian coins. The weights of the coins varied between 1.89 and 11.46 g while their thicknesses ranged from 0.10 to 0.40 mm. The elements; Al, Si, Mn, Fe and Zn were detected along with the major components of Ni and Cu. The elements displayed both positive and negative correlations. The study could aid in solving some scientifically questions of conservators and tourists on “what” material is it especially now that coins have long been demonetized in Nigeria.

Keywords: archaeology, coins, composition, numismatic, PIXE.