Mr Ahmed Khairy, Ms Asmaa Mattar, and Mr Ahmed Tarek
Abstract
This paper presents the findings of a conservation treatment and research project on a Late Period ancient Egyptian miniature wooden coffin from the Egyptian Museum in Cairo. The coffin, which contains a mummified organ, exhibits a fragile polychrome surface with a variety of traditional Egyptian pigments. The primary challenge was to perform a thorough sterilization to eliminate insect and microbial threats without altering the delicate and historically significant painted surface. This study investigates the efficacy and potential side effects of anoxia, a widely used but not fully characterized conservation method, on ancient pigments.
The project involved placing the coffin in a sealed anoxic environment where oxygen was displaced with humidified nitrogen gas. The oxygen level was reduced to less than 0.02% and maintained for two weeks. Throughout the treatment, a suite of non-invasive analytical techniques, including multispectral imaging (MSI), X-ray fluorescence spectrometry (XRF), and spectrophotometry, was employed to monitor the pigments. These techniques allowed for the identification of the pigments—including orpiment, red ochre, and Egyptian blue—and a precise measurement of any color changes before and after the anoxic treatment.
The results demonstrated that the anoxic sterilization process was highly effective in creating an environment lethal to aerobic organisms. Crucially, the spectrophotometric data revealed no significant changes in the color or lightness of the pigments. The findings of this research provide critical validation for the use of nitrogen-based anoxia as a safe and effective method for the sterilization of polychrome wooden artifacts. This study contributes new knowledge to the field of conservation by providing empirical evidence that anoxic treatment does not adversely affect the stability of common ancient Egyptian pigments, thus offering a reliable and non-damaging solution for the preservation of similar cultural heritage objects.