Black fungi in marble and limestones — an aesthetical, chemical and physical problem for the conservation of monuments

The interaction of black fungi such as Phoma and Alternaria with marble surfaces, the pattern of growth of these organisms and the causes and reasons of physical and chemical damage are described. Special attention is given to the penetration pattern of the organisms under study as well as to their capability of altering the colour and mineralogical composition of rock surfaces. Some attention is given to special techniques of differentiating between different pigmentations of rock surfaces from cultural monuments. Further we discuss future techniques and approaches, which can be developed and used to protect the rock surfaces from this damage.