Potential of reflected light microscopy as a non-invasive identification tool on wooden cultural artefacts – preliminary results

Species determination is a crucial step in wooden cultural artefacts diagnostic process. Not only it actually represents the key to physical and mechanical properties of a wooden object, but a precious instrument for its cultural understanding too. Scientific wood identification by microscopic analysis currently represents the most reliable and practicable technique. Since both this method is affected by biological limitations and most of the artefacts present sampling limitations, it is however impossible to predict end result accuracy and hence survey usefulness. Non-invasive alternatives to the common sampling procedure are hence preferable, when not necessary in the case of objects that do not permit sampling at all. Objective of this paper is to present some preliminary results of a study held in order to evaluate the usefulness of reflected light microscopy as a noninvasive identification tool. Different surfacing and finishing treatments with reference to typical ancient manufacturing methods were reproduced on selected species. The visibility of anatomical features was then evaluated on the basis of a four level scale. Two indexes were created to evaluate both differences between treatments effects and single anatomical feature hardness of identification. Surfacing affected anatomical features visibility at different degrees of severity depending both on adopted technique and species, while finishes partially improved or worsened it. Each anatomical feature demonstrated to have different susceptibility towards treatments, showing distinct identification hardness. For an evaluation of the reflected light microscopy potential as a non-invasive identification tool, a further study aimed to evaluate the efficacy of polarized and narrow-band filters has been fixed up.