Honeycomb Weathering of Sandstone Outcrops at Al-Hijrv(Mada'in Salih), Saudi Arabia

Honeycomb weathering, characterized by the formation of honeycomb-like patterns on sandstone surfaces due to salt weathering, significantly impacts the preservation of the Nabataean rock-cut tombs at Al-Hijr (Mada'in Saleh), a UNESCO World Heritage Site in Saudi Arabia. The study identifies that this phenomenon is driven by variations in the rock's properties and the repeated wetting and drying cycles, leading to the flaking of thin layers from the lower parts of the sandstone outcrops. Investigations using field observations, Optical Microscopy (OM), Polarized Microscopy (PM), Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM-EDS), and X-Ray Diffraction (XRD) revealed that Al-Hijr sandstones consist of fine to large grained minerals, predominantly quartz (SiO2), halite (NaCl), ringwoodite (Mg2SO4), and kaolinite (Al2Si2O5(OH)4). These findings provide a critical diagnosis for developing effective conservation strategies to mitigate the degradation of this historically significant site.

M., S. (2013). HONEYCOMB WEATHERING OF SANDSTONE OUTCROPS AT AL-HIJRv(MADA’IN SALIH), SAUDI ARABIA. Egyptian Journal of Archaeological and Restoration Studies, 3(2), 85–93. https://doi.org/10.21608/ejars.2013.7278