The colour of architecture: physical-chemical analysis of polychromy on stone in a 16th century gothic Portal at the Cathedral of Santo Domingo

Abstract

Colour always played a role in the human evolutionary process and has been used as a way of expression. But the time, the lack of maintenance and abandonment, the lack of studies related to the presence of polychromy in architecture and the nineteenth-century idea of eliminating building plasters to expose stone and brick have caused many to ignore and forgotten the presence of colour in historical buildings. In most cases disappear leaving only traces of colours. For this reason the aim of this research is study the polychromy on stone of a 16th century gothic Portal in the Cathedral of Santo Domingo. Analyses were performed using non-destructive techniques as Transmission Polarized Light Microscopy (PLM), Fourier- Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy / Energy Dispersive Elemental Analysis X-Ray (SEM/EDX), Gas Chromatography (GC) and X-Ray Diffraction (XRD). To determinate the colour was used a CIELAB System and Munsell Colour System. In conclusion patinas yellow, ochre, red, green and blue colours; and pigmented successive layers of plaster and lime was found. Remains of these layers of polychromies are also spread throughout many areas of the Cathedral.