Scientific studies on decorated mud mortar of Ajanta

• Scientific investigation of earthen plaster of Ajanta.
• Replication of ancient mud mortar for conservation of earthen plaster.
• The presence of rare aggregates of glauconite and zeolite in ancient earthen plaster.
• The presence of sepiolite enhances the performance of earthen plaster.

This study is an attempt to reveal the decorated earthen plaster of Ajanta. The mud plaster of Ajanta caves has been analyzed with the help of physical and analytical tools. The results indicate that high silt (>70%) low clay soil may have been mixed purposefully with lime (calcite) for the reason to enhance the cementing characteristics. The presence of calcium oxalate was detected from FTIR spectra may have been the resultant product of proteic materials presented in mud plaster. Ferrugineous silicate along with rarer gluconite–celendonite and white zeolites were also perceived from SEM and FTIR spectral analysis. The existence of quartz and sepiolite in mud mortar was also detected from XRD and SEM studies. The vegetal matter might have been added to tailor the construction behavior. The analytical results authenticate the similarity of earthen plaster of Ajanta and alluvion deposits of Waghura River just in front of caves, probably used as raw material in improvement of new material that suits for restoration for optimize performance and compatibility with the existing materials.