X-Ray Fluorescence
X-ray fluorescence (in short XRF) spectrometry is an analytical technique used to investigate the elemental composition of materials. Although it is not capable of detecting light elements (typically elements lighter than Aluminium, Z=13), it is widely used in the field of cultural heritage for being non-invasive and non-destructive, and being available in a range of different configurations, from hand-held portable devices to larger high-resolution scanning spectrometers. After the analysis, a spectrum is obtained, whose peaks correspond to characteristic patterns of X-ray emissions from atoms irradiated with the incident beam. As the peak height for emission is directly related to the concentration of the corresponding element within the sampling volume, quantitative analysis is theoretically achievable, although in practice, this is limited to prepared homogeneous samples such as pressed pellets (thus losing the advantage of being non-destructive). Most of the time, XRF in archaeometry will be limited to qualitative and semi-quantitative analysis, which proved already extremely useful to discriminate between inks.