Pigment and plasterwork analyses of nasrid polychromed lacework stucco in the Alhambra (Granada, Spain)

This paper deals with the description of the stucco (decorative plasterwork) and pigments used in the Alhambra (Granada, southern Spain). The nature, structure and deterioration of these materials are described in detail, as well as the painting and stucco techniques employed. A cast plaster technique is found throughout the Lions Palace (late Nasrid period, second half of the fourteenth century), whereas plaster carved in situ is only found in certain areas of the Partal Palace, one of the oldest constructions still extant in the Alhambra (1302-1309). Two original Nasrid palettes were also identified: an earlier, simpler palette of blue, red and black, and a later, more varied palette of red, blue, green, black and gold. In both cases white was the background colour. The gold decoration technique is described, as are the Christian interventions. Rich pigments were used throughout the history of the Alhambra (e.g. gold, lapis lazuli, azurite, malachite, cinnabar and red lead). Some pigments, red lead and malachite in particular, are severely decayed through introduction of chloride-based materials, resulting in discolorations. Cracking and loss of gold decoration is widespread. The paper gives the first description of the Nasrid palette used to colour the Alhambra stucco, as well as the gilding and the plasterwork techniques. These pioneering results clarify historical and artistic issues.