Residues on stone artefacts : state of a scientific art
It is a startling experience to look down a microscope at a stone tool — a real Palaeolithic artefact, not a modern thing or a replicated copy — and see on its flint surface grubby brown-red stains that look the colour of old blood. Is a consensus emerging from the archaeological scientists as to just what traces of, especially, biological materials do survive on ancient stone surfaces, where they can be reliably characterized and identified?
Fullagar, Richard; Furby, Judith; and Hardy, Bruce, "Residues on stone artefacts : state of a scientific art" (1996). Antiquity 70(270): 740-745. Faculty Publications. Paper 43.