Characterization and origin of weathering crusts on Kylin carved-stone, Kylin countryside, Nanjing – A case study

To evaluate the effects of the environment pollution on weathering of outdoor stone artifacts in Kylin countryside, Nanjing, a Kylin carved-stone was studied accordingly to the observable decay pattern on its surface. Different samples were collected either from the deteriorated areas or from the sound stone substrate. The samples were characterized by IR, XRD, XRF, SEM, IC and ICP techniques. Gypsum, kaolinite, calcium oxalate and phosphate together with an high content of heavy metals and soil particulates are mainly located on sheltered or partially exposed areas, while an extensive network of parallel fissures is mainly developed on surfaces directly exposed to rainwater. Furthermore, an extensive colonization by lichen is affecting a wide surface of the carved-stone, which is strongly adherent to the surface. The obtained results show that the deterioration is mainly due to the atmospheric pollutants and its extent is strongly dependent on the surface exposition to the environment.