A study by the Academic Laboratory of Materials Research of Paintings (ALMA) in Prague, Czech Republic has shown that X-ray powder micro-diffraction can be used for the investigation of salt damage. The use of X-ray microdiffraction enabled the research team to identify the probable causes of damage to an ancient fresco.
Pigment degradation, often resulting in color changes, causes serious damage to wall paintings. Many factors lead to pigment degradation including sunlight, air pollution, salts and microorganisms. Of these, salts are one of the most damaging agents, especially for artworks of a porous nature such as wall paintings.