Comparison of brass alloys composition by laser-induced breakdown spectroscopy and self-organizing maps

•A method for assessing the similarity of materials analyzed by LIBS is proposed.•Two very similar fragments of historical brass were analyzed.•Using a simple artificial neural network the composition of the two alloys was determined.•The composition of the two brass alloys was the same within the experimental error.•Using self-organizing maps, the probability of the alloys to have the same composition was assessed.

In this paper we face the problem of assessing similarities in the composition of different metallic alloys, using the laser-induced breakdown spectroscopy technique. The possibility of determining the degree of similarity through the use of artificial neural networks and self-organizing maps is discussed. As an example, we present a case study involving the comparison of two historical brass samples, very similar in their composition. The results of the paper can be extended to many other situations, not necessarily associated with cultural heritage and archeological studies, where objects with similar composition have to be compared.