Building Materials Assessment from Amenemhat III’s Pyramid at Dahshour (Giza, Egypt)

The Pyramid of Amenemhat III, also known as the Black Pyramid, is one of the earliest pyramids constructed primarily from mudbricks, and later encased with limestone. Built during Egypt’s Middle Kingdom (c. 1860–1814 BCE), it reflects an important transition in ancient Egyptian architecture, balancing the grandeur of traditional pyramid design with the economical use of mudbrick as a core material. This study provides a comprehensive analysis of the pyramid’s construction techniques, material composition and preservation challenges, integrating field observations with advanced analytical methods, including X-ray diffraction, X-ray fluorescence spectroscopy, and petrographic microscopy. The research highlights a sophisticated material strategy to select locally sourced materials, using a core of phyllosilicate-rich mudbrick enhanced with organic additives for flexibility and cohesion, and calcite-dominated limestone casing chosen for its protective and aesthetic qualities. However, the pyramid has largely eroded over time and faces significant conservation challenges. Swelling clays, salt crystallization, and thermal stress have contributed to the degradation of the mudbrick core, while environmental and anthropogenic factors have accelerated the erosion of the limestone casing. The results emphasize the ingenuity of Middle Kingdom architects in resource efficiency and structural innovation, while also identifying vulnerabilities in the used materials. Finally, this study not only deepens the understanding of ancient Egyptian construction practices but also provides a foundation for sustainable conservation approaches to safeguard this monumental heritage.