animal glue, etc.) to achieve the adhesion between the particles and consequently to be applied as paint film on the dry ground. The pigment must be dispersed or grinded as evenly as possible in the binding medium to take full advantage of the properties of both the pigment and the binder.[8] The typical stratigraphic structure of the Egyptian wall paintings is usually made of multiple layers. The plastering procedure was to initially smooth an irregular rock surface with one or more of plaster layers. The first layer is the coarse, so called ‘arriccio’, applied directly to the wall. This layer consists of siliceous aggregates, and the matrix binder is mainly of gypsum or lime. The second intermediate layer is the fine plaster called ‘intonaco’, …show more content…
Egyptian blue was the first synthetic pigment ever produced by man; it is considered a great technology development in the ancient Egypt, as it appeared in Egypt during the third millennium BC. [9] This pigment consists of the mineral cuprorivaite (CaCuSi4O10), a blue tabular crystal about 15–30 mm in length, residual silica (quartz and/or tridymite) and an amorphous silica-rich phase. This pigment was made by mixing calcium salt (carbonate, sulfate or hydroxide), a copper compound (oxide or malachite), sand (silica), and an alkali flux (sources of alkali could either have been natron from areas such as Wadi Natrun and El-Kab, or soda-rich plant ashes).[10] This mixture then is heated to produce a colored glass or frit and ground to a powder.[11] Synthesis of the pigment can be summarized as follows: a mixture of quartz, calcium salt, copper salt or copper carbonate (malachite), and flux such as soda or potash are heated at 900–950 C under normal atmospheric conditions for 24 h[12,13] according to the following equation:[14] Figure 1. (a) A general view of the exterior of the temple of Hathor. (b) A plan of the temple. (c) A column representing the well-known shape of