Red resins, lapis lazuli and vermilion: High symbolism luxury pigments identified in a Bifaz from the late fifteenth century preserved in the Camp del Turia (Valencia)

The use of red resins to represent the blood of Christ began to be frequent in the Middle Ages. These additives of organic origin had a viscous texture and a color that resembled the vital liquid, and that contributed to give more realism to the Passion of Christ. The study of the pictorial film of a Bifaz of the late fifteenth century from Camp del Turia (Valencia) has been developed in the Laboratory of Analysis and Diagnosis of Art Work of the University of Valencia, and the Science Park of the same institution, using techniques such as Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography-Mass Spectrometry (GC-MS). Both techniques have revealed the employ of a resin colored for this purpose, and other materials of great importance and tradition in the representation of the sacred images of Christianity, as is the case of the blue pigment that was used in the veil of the Virgin: the expensive lapis lazuli. This mineral, from the pigment was made, is a complex sulfur-containing sodium aluminum silicate (Na,Ca)₈(AlSiO₄)₆(SO₄,S,Cl)₂. The cost of some of these raw materials, given their distant origin, allows relating the artistic production of this icon with a high color economy, and a strong religious symbolism.