Sandstone bleaching refers to the process in which the natural color of sandstone is altered or lightened due to various factors such as weathering, exposure to sunlight, chemical reactions, and biological activity. This phenomenon can result in the loss of the original color and aesthetic appeal of the sandstone. Researchers in this area study the mechanisms and factors that contribute to sandstone bleaching, as well as potential methods to prevent or reverse this process. This research is important for preserving the natural beauty and durability of sandstone structures and artworks.