Identification of materials in objects of the cultural heritage is important for several purposes: (i) it is necessary to design and apply effective conservation treatments; (ii) it provides valuable historical information, useful for the history of art; (iii) it is essential in documenting the evolution of the materials/ techniques used in creating objects over the centuries; and (iv) it sometimes helps to authenticate and date the object.
The objective of this work is the characterization of materials, which are contained in wall paintings in three Macedonian tombs: the tomb I of Dion (Sotiriadis), the tomb IV of Dion (Karitsa), and the tomb A (Heuzey). Attention is focused on the identification of pigments which were used in the wall paintings of the three burial monuments. Our goal is, therefore, to enrich the rather limited available data regarding the coloring materials that are included in the palette of the Macedonian cultural heritage. Moreover, the results could be useful to design and apply effective conservation treatments in the future. To the best of our knowledge, this is the first attempt to identify the colorants of the wall paintings in the three aforementioned Macedonian tombs.
The investigation is carried out in two phases. The first approach is to use non-invasive, portable X-ray fluorescence (XRF) spectroscopy for in situ measurements which are carried out in several areas of the wall paintings of the tombs. In the second phase, 12 samples, which were removed from damaged areas of the wall paintings, are investigated using optical microscopy (including stereomicroscopy), micro-Raman and micro FTIR spectroscopyspectroscopy as well as scanning electron microscope combined with energy dispersive X-rays (SEM-EDX) spectroscopy. These techniques, employed herein, are nondestructive for the integrity of the extracted valuable samples.
According to experimental results the following pigments were identified in the investigated samples: hematite, yellow ochre, Egyptian blue, calcite and carbon black. Moreover, the high content of calcium (Ca) detected in all samples, suggesta that the fresco technique was applied for the construction of the wall paintings, while the presence of an organic material in three samples, allows us to assume that the secco technique was also used in combination with the fresco.
