In the paper are presented results of more
than 550 analyses carried out on wall painting fragments and raw pigments from
14 different Roman sites in Switzerland as well as Pompeii. 28 different
pigments are identified: 7 whites (aragonite, chalk, slacked lime, dolomite,
ring-white, cerussite and diatomite); 7 reds (hematite, red ochre, burnt
goethite, cinnabar, red lead, sandyx and some peculiar lead-based pigment); 5
greens (celadonite, glauconite, chlorite, malachite and verdigris); 3 blacks
(soot, charcoal and bone black); 1 blue (Egyptian blue); 1 brown (brown ochre);
1 grey (ash); 3 yellows (goethite, yellow ochre and clavey marne). In the light
of these results, some anomalies concerning both published analyses and
interpretations of the texts of Vitruvius and Pliny are discussed. In
particular, the confusing pigments terminology, attribution of detected
pigments to those mentioned by the texts, nature and origin of certain
pigments, limit and riliability of analytic data, exploitation of local pigment
resources and finally the relationship of pigments gamut and pictorial
technique and to painting workshops.
keywords: Roman wall painting: materials, techniques, analysis and conservation