Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. salt (inorganic material)

Anotations

Scope note:

Soluble salts are dissolved minerals whose crystallization on the surface and in the substrate of materials causes efflorescence and deterioration.The presence of water-soluble salts is a key factor in the degradation of masonry and other highly porous stone building materials. Surface efflorescence is a serious threat to ancient mural paintings. Conservation seeks to identify soluble salts in objects affected, and extract them or otherwise halt the degradation they inflict.