The Curse of the pXRF: the Negative Consequences of the Popularity of Handheld XRF Analysis of Copper-Based Metal Artefacts

Abstract

In this paper I shall explore some of the negative consequences of the current popularity of portable X-ray fluorescence (pXRF) analysis. There is no doubt that this portable device, which can be taken to museums and sites, has revolutionised the study of the compositions of many classes of archaeological material, but the apparent simplicity of its operation and the generation of analytical results has also created problems, particularly as regards the analysis of metals. Many archaeologists and museum curators do not seem to understand that pXRF data generally does not reflect bulk composition of copper-based metalwork. PXRF analyses the surface of an artefact, which is of course subject to weathering and alteration, and, moreover, some elements segregate or enrich on the surface of objects during metallurgical processes. A further problem is that it is becoming more and more common for museum curators to refuse to authorize destructive methods of analysis since pXRF analysis can be effected without damage to ancient artefacts. The misunderstanding by many archaeologists and curators of the nature and significance of pXRF is illustrative of the misunderstandings that exist between materials scientists and archaeologists.