Calcium carbonate latter is especially evident in day-to-day life of people who have hard water. Water in aquifers underground can be exposed to levels of CO much higher than atmospheric. As such water percolates through calcium carbonate rock, the CaCO dissolves according to the second trend. When that same water then emerges from the tap, in time it comes into equilibrium with CO levels in the air by outgassing its excess CO. The calcium carbonate becomes less soluble as a result and the excess precipitates as lime scale. This same process is responsible for the formation of stalactites and stalagmites in limestone
Sittanavasal Cave ASI) were applied over dry plaster surfaces without any adhesive grove; the process involved a chemical reaction of lime water which absorbed oxygenin the air and getting converted by a carbonisation process into insoluble calcium carbonate, which enabled the pigments to adhere to the surface. At the initiative of Pudukkottai State, during 1937–39, the paintings were cleaned, and then given a preservative coating. Also, the damaged portions of the plastering were injected with cementing material and the paintings were also retouched. The condition of paintings are deteriorating. Sittanavasal Cave Sittanavasal Cave (also, Arivar Koil) is a 2nd-century Jain complex of