Kathleen M. Garland, John Twilley, Johanna Bernstein, and Joe Rogers
Abstract
The examination and treatment of the polychromed and gilded coffin of Meret-it-es was an effort requiring the participation of conservators, conservation scientists, the curator, preparators, a designer, wood scientists, and a structural engineer. The unusual ochre color on the inner coffin was found through SEM investigations to be the result of the transformation of red realgar into pararealgar and possibly into orpiment, substantially altering the appearance of the coffin. SEM also revealed oxidation of these arsenic-containing pigments into arsenic oxide. A widely-applied copper green is a pigment previously unidentified in the Egyptian palette. Consolidation of the fragile, tented paint using Paraloid B-72 will be discussed. Space requirements made it necessary to display the coffin upright, but x-ray radiography indicated that the aged Ficus wood has areas of potential weakness. Transmission ultrasound measurements (Sylvatest Duo, 22kHz) were collected, and mechanical properties such as specific gravity, modulus of elasticity, and compression (parallel to the grain) of the wood were estimated to evaluate the potential stress of raising the coffin upright. A handheld Leica HDS 6000 laser and AT-901 laser tracker with T-Scan were used to capture point clouds of the inner coffin laying flat and then when raised to nearly vertical. This was done to see more precisely what movement, if any, might occur in the wood, as well as to serve as a long-term baseline to monitor potential movement over time. This evaluation of the wood was used to engineer a minimally intrusive mount to reduce long-term stress by displaying the coffin at an incline of 5 degrees off vertical.