Characterization of İscehisar Andesite (Afyonkarahisar-Turkey), Used as a Building Stone Source of Historical Heritages from Ancient Times to the Present

Most historical structures that have survived to the present day are constructed from natural stones. One such natural stone is andesite. This study conducted a series of characterization studies on andesites used as building stones in Afyonkarahisar (Turkey). The building stones in question were determined by the petrographic-mineralogical (polarizing microscope, XRD, SEM), chemical, pore diameter distribution, and physico-mechanical properties. Although the İscehisar andesite is not as well-known as the İscehisar marble, it is a volcanic rock widely used in cultural heritage sites such as mosques, fountains, and bridges that have survived from the Seljuk and Ottoman periods to the present day in Afyonkarahisar. Despite the presence of pink, brown, and gray-black colors in the İscehisar andesite, it is evident that the preference in historical buildings is mainly for gray-black variants. Andesite, marble, and limestone, such as İscehisar Bridge from the Hellenistic period, Kırkgöz Bridge from the Byzantine era, Altıgöz Bridge from the Seljuk period, and Kanlı Göl Bridge from the Ottoman period, were used together in various combinations. Mosques are another group of structures in which andesite and other volcanic rocks are heavily used, such as bridges. While tuff is commonly used in examples of Seljuk and Ottoman architecture that have survived to the present day, andesite and other volcanic rocks along with bricks have also been used to construct dozens of mosques. Andesites found in the İscehisar region continue to be widely extracted, cut, and shaped using different surface processing techniques and are used today.