A key to identify use-related micro-residues on prehistoric stone artefacts using Raman spectroscopy

•Raman microscopy has become a useful tool to identify in situ micro-residues.•We develop a key to assist in classifying residues with respect to their origins.•Raman spectroscopy is used as the first step, complemented by optical microscopy in the second step.•Raman microscopy can play a pivotal role in initial screening and analysis of residues.