The study of the alteration processes of metals, such as lead, bronze, iron and tin-mercury alloys, used in some of the
most important chosen artefacts of Andalusian Cultural Heritage is the main objective of this paper. Hydrocerussite
and cerussite were detected in lead seals stored in a hole of cardboard. Bronze is altered to atacamite by environmental
contamination, which is also responsible for the formation of rust from iron. Corrosion of the tin-mercury surface
of amalgam mirrors produces tin monoxide and tin dioxide and releases liquid mercury from the solid phase.