This Many kinds of microorganisms are playing key role in degradation of historical artifacts, buildings and monuments made of marble, granite and other dimension stones. It is well known that, photoautotrophic microorganisms predispose the stone surface as a breeding-ground for other group of microorganisms. However, the effects of photoautotrophic and other microorganisms on stone materials, where hygiene is crucial, are not well known. Until now, the relation between microorganisms and rock properties and its effect on usage is not investigated. In this study; the biological weathering of AW (true marble) and BP (granite) has been investigated in laboratory condition. Both stone surfaces also supported a heavy colonization of phototrophic microbial consortia (outer and inner part, respectively). After phototrophic microbial growth on AW and BP, while AW turned to yellowish green from original white color, BP turned to green from original grey color. Inner sides of stones, filamentous biota, are possible member of cyanobacteria, were dominant. However, small spherical aggregates, possible calcified globular bodies on the stones were detected with SEM studies.