Smartphone photos as a non-destructive approach to characterise siliceous artefacts

A methodological proposal was developed for the study of prehistoric siliceous artefacts which includes the use of smartphone photography as an analytical tool. Different kinds of materials (cherts, rock crystal and quartzite) were sampled from the lithic assemblage of La Calvera rock-shelter (Camaleño, Spain), chosen as a case study. Each sample was photographed with a smartphone and colour features were compared with portable and non-destructive standardised techniques including visible spectrophotometry, Raman, diffuse reflectance Fourier transform infrared spectroscopy and portable X-ray fluorescence. The obtained results suggest that smartphone image analysis is a reliable approach to characterise siliceous rocks and that it can be a valuable, cheap and fast method especially suitable for the first screening of large lithic assemblages.