Delamination
Stone delamination is a condition of stone in which the outer surface of the stone splits apart into laminae or thin layers and peels off the face of the stone. Once delamination begins, there is almost nothing that conservation efforts can do to reverse the process.
In the image above, stone delamination on the second floor of Angkor Wat Temple has begun to destroy these 12th century devatas.
Also in Angkorpedia
