Charakterystyka i stan zachowania kamienia użytego do budowy oraz dekoracji kościoła kolegiackiego pw. św. Anny w Krakowie

One of the most beautiful churches in Kraków is the St. Anne’s collegiate, situated in the city centre. This localisation has a significant impact on destruction of the structure and decorative stones of the church. The sandstones and limestones of the structure outer part are exposed mostly to seasonal climate changes and anthropogenic pollution. The stone alterations are expressed mainly as surface build-ups with grey colours. Disintegration of the surface stone layers as a result of mechanical weathering, biodeterioration, efflorescence processes, exfoliation and scaling off sandstones due to hydration and dehydration of secondary salt minerals are other signs of stone damage. Green coloration of sandstone entrance stairs due to precipitation of copper carbonate (malachite) negatively affects the aesthetics of the church front. The interior stone decoration is represented essentially by limestones used mainly as the floor tiles. These are varieties of compact limestones, whose attractiveness results from their diverse colours, the presence of fossil fragments and calcite veins, and good cutting and polishing properties. The preservation of the limestone masonry depends on the rock type and the place it is used in. Considering the historic and architectonic values of this church, the most splendid example of the Baroque sacral architecture in Kraków, a special care in the selection of appropriate conservation methods must be taken to preserve to posterity the appearance and beauty of the collegiate.