Bakerian Prize Lecture by Professor Robin Clark CNZM FRS, University College London
Raman spectroscopy is a light scattering technique primarily used in the characterisation of vibrational modes of molecules and therefore in assessing the structure and composition of materials. When the light source such as a laser is coupled to a microscope, the resulting technique - Raman microscopy - is now recognised to provide very effective means for the identification of micrometre-sized grains of any material such as a pigment. The technique has the attributes of sensitivity, reproducibility and high spectral (c. 1 cm-1) resolution, along with those of being non-destructive and applicable in situ. It is thus appropriate to artwork and artefacts from which sampling is either undesirable or prohibited.
The lecture will be illuminated with studies leading to the rapid and effective identification of pigments on manuscripts, paintings, papyri, icons, ceramics and archaeological artefacts, leading to the establishment of artists' palettes at different periods and in different localities, together with comments on related scientific studies at the Arts/Science interface bearing upon restoration, conservation and dating of artefacts and the detection of forgeries. Rarely has an optical technique made such an impact on seemingly unrelated disciplines.