Raman microscopic and computational studies of artists' pigments and molecular inorganic compounds
This thesis is principally concerned with spectroscopic and computational studies of
artists' pigments. Manuscripts, art and archaeological artefacts were examined by
Raman microscopy, identifying the pigments and drawing conclusions for historical and
Studies of Anglo Saxon and later manuscripts have shown the Insular palette
triumvirate, assumed to be orpiment, red lead and verdigris, to contain red ochre and
vergaut, but no verdigris. This remains unchanged until the introduction of lazurite in
c. 920 AD and vermilion in the 12th century. Lazurite has been erroneously identified on
the Lindisfarne Gospels, by the technique of Roosen-Runge. Raman microscopy shows
the blue pigments to be exclusively indigo, casting doubt on analyses performed using
The Islamic manuscript palette was found to be remarkably consistent across a
substantial geographical area over an extended period. It is also very similar to that of
early Western manuscripts. Comparison of these results with existing literary sources
has shown the latter to be highly inaccurate.
The palette of William Blake was examined and compared to results of analysis by
False Colour Infrared Photography (FC-IP). The FC-IP technique was determined to be
inappropriate for pigment identification.
Two significant artefacts were shown to be modern forgeries: a rare Assyrian fresco
contains a modern green pigment, and the world famous Vinland map was found to
have significant quantities of anatase in the yellow lines.
Density Functional Theory methods were applied to the mechanism of decay
isomerisation of As4S4, which was partially clarified, and to the geometries of R2SeX2
(R = CF3, CF2H, CFH2, CH3, CH2CH3, CH(CH3)2, t-Butyl, X=F, Cl, Br, I, At). The
most stable geometry was found to be determined by the polarity of the Se-X bonds and
the steric and electron-withdrawal effects of the R-group on the C-Se bond strength.