Material characterization and restoration of mural paintings of El-Muzzawaka Tombs, Dakhla Oases, Egypt

Abstract

The present study demonstrates scientific procedures applied to study mural paintings in two Graeco-Roman tombs of El-Muzzawaka, Dakhla Oases, Egypt. First, a series of analytical methods was applied to determine the chemical and mineralogical composition of pigment and plaster samples collected from the studied tombs. The analyses were performed by means of digitalized optical microscopy (OM), polarized light microscopy (PLM), scanning electron microscopy attached with X-ray microanalysis detector (SEM−EDS), X−ray diffraction analysis (XRD), and Fourier transform infrared spectroscopy (FT−IR). Analyses of the pigment samples revealed Egyptian blue, Egyptian green, green earth, black magnetite, and red/yellow ochres. The paintings were applied on a coarse plaster layer made of gypsum, anhydrite, calcite, and quartz. The preparation layer was made of two phases of calcium sulphate (gypsum and anhydrite). Further, the detection of an organic binder, of gum Arabic, confirms the application of tempera technique. The results showed that the bed rock samples contain variable amounts of quartz, anhydrite, montmorillonite, kaolinite, gypsum, and sodium chloride (halite). In situ observations showed several deterioration forms on the studied mural paintings. The destructive climatic condition of the region and the defects of the rock structure have contributed seriously in the deterioration process. Based on experimental tests, multi restoration procedures were applied in form of cleaning, reattaching paint flakes, applying injection grouts to detached layers, reconstruction of missing parts in the plaster, repair of wide-open cracks, and final protective consolidation of the painted surfaces. Further, recommendations to minimize any future damage were discussed.

Examination and Analysis of a Painted Wooden Funerary Stela From the Late Period at the Egyptian Museum in Cairo

“…The results of the red analysis also proved to be made of hematite Fe 2 O 3 , an ochre pigment that was by far the most commonlyused pigments in ancient Egypt and used from the pre-dynastic period onwards [29]. The analysis of the green color proved that it was made of Egyptian green, a synthetic pigment similar to Egyptian blue but based on silica-rich copper glass, and its manufac-turing process requires higher temperatures and large amounts of alkali [30].…”

Characterizing the Painted Wall Reliefs From the Ancient Egyptian Rock Tombs of Meir at Assiut, Egypt

“…The ancient Egyptians used carbon black from many sources such as soot, charcoal, charred bones, and in some cases, magnetite (Fe 3 O 4 ). The latter was reported mainly in decorations from Graeco-Roman tombs in the Western Desert of Egypt [26].…”

A Case Study of Renaissance Wall Paintings in Granada (Spain): Historical–Artistic Analysis, Materials Characterization, and State of Conservation

“…Saline efflorescences are one of the major deterioration forms present here and arise as a result of humidity filtration, both on the surface of the paintings and in depth. Salts are very destructive because they have a great water absorption capacity (i.e., hygroscopicity) and end up modifying the water behavior of the wall and giving rise to chromatic alterations [4,10,53,54,56,57]. When the wall dries, the saline solution can undergo a crystallization process that triggers further degradations: the salts present in the pores crystallize and may destroy the internal structure of the materials that can be manifested as a loss of painting, detachment of the pictorial layer, swelling, and pulverulence (among others), very common in the deterioration of wall paintings Saline efflorescences are one of the major deterioration forms present here and arise as a result of humidity filtration, both on the surface of the paintings and in depth.…”

“…When the wall dries, the saline solution can undergo a crystallization process that triggers further degradations: the salts present in the pores crystallize and may destroy the internal structure of the materials that can be manifested as a loss of painting, detachment of the pictorial layer, swelling, and pulverulence (among others), very common in the deterioration of wall paintings Saline efflorescences are one of the major deterioration forms present here and arise as a result of humidity filtration, both on the surface of the paintings and in depth. Salts are very destructive because they have a great water absorption capacity (i.e., hygroscopicity) and end up modifying the water behavior of the wall and giving rise to chromatic alterations [4,10,53,54,56,57]. When the wall dries, the saline solution can undergo a crystallization process that triggers further degradations: the salts present in the pores crystallize and may destroy the internal structure of the materials that can be manifested as a loss of painting, detachment of the pictorial layer, swelling, and pulverulence (among others), very common in the deterioration of wall paintings [7,53,54,56,58,59], all of which are present in the wall paintings that are studied here (Figure 5a,b).…”

“…Salts are very destructive because they have a great water absorption capacity (i.e., hygroscopicity) and end up modifying the water behavior of the wall and giving rise to chromatic alterations [4,10,53,54,56,57]. When the wall dries, the saline solution can undergo a crystallization process that triggers further degradations: the salts present in the pores crystallize and may destroy the internal structure of the materials that can be manifested as a loss of painting, detachment of the pictorial layer, swelling, and pulverulence (among others), very common in the deterioration of wall paintings [7,53,54,56,58,59], all of which are present in the wall paintings that are studied here (Figure 5a,b).…”