The Raman spectra of specimens of the 11th century mediaeval wall paintings
from the small, isolated monastery of San Baudelio de Casillas, Soria, Spa
in, have revealed a color palette based on haematite, charcoal/soot, lithar
ge, goethite, minium, and a copper salt (probably malachite or verdigris).
Unlike other mediaeval artworks of the same period found in Castille y Leon
in the northern part of the Duero River (Burgos and Leon), which contain a
rich blend of pure and mixed pigments such as cinnabar, realgar, orpiment,
barytes, and lapis lazuli, none of these are found to occur at this site.
Similarly, litharge has not been identified previously at these other sites
north of the Duero River. The materials found in the present study were pr
obably all available in the immediate vicinity of the monastery and confirm
the recorded history that the inhabitants were of a closed order from the
Arabic kingdom of Cordoba, with little outside contact.