Raman spectroscopy is a light scattering technique primarily used in assessing the structure and composition of materials. When a light source such as a laser is coupled to a microscope, the resulting technique – Raman microscopy – is now recognised to provide effective means for identifying micro- to nano-metre sized grains of any material such as a pigment. The technique now has the attributes of sensitivity, reproducibility, high spectral resolution, and in situ operation. As it is also non-destructive, it is highly suitable for working on pigment or dye identification on valuable artwork and artefacts. The so-called Raman effect takes its name from its discoverer in 1928, C.V. Raman, who was awarded the Nobel Prize for physics in 1930.
The lecture will highlight studies leading to the 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. These results, together with other related scientific ones at the Arts/Science interface, bear upon the restoration, conservation and dating of artefacts and the detection of forgeries. Rarely has an optical technique made such an impact on seemingly unrelated disciplines.
Born in Rangiora and a graduate of Canterbury University, Robin Clark is an internationally celebrated scientist, based at University College London where he was for many years the Sir William Ramsay Professor, Dean of Science and Head of Chemistry, recently becoming Ramsay Professor Emeritus. He is a Fellow of the Royal Society of London and Member of the American Philosophical Society, and was recently awarded the Franklin-Lavoisier prize for his work in Raman microscopy. Professor Clark has been involved in the examination of some of Europe’s best known artwork such as the Lindisfarne Gospels, Gutenberg Bibles, ‘old masters’ including Vermeer’s Young woman seated at a virginal, rare postage stamps, old maps, artefacts from Samarra, China,etc., and in the detection of forgeries from Egypt, Spain and elsewhere.
Date: Thursday 31 March
Location: Soundings Theatre, Te Papa