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
Speleogen Speleogen A speleogen is a geological feature within a karst system that is created by the dissolution of bedrock. As rain water falls through the atmosphere it picks up carbon dioxide and more as it passes through organic material in the soil. As water moves through joints and cracks in calcium carbonate bedrock, more dissolution of the bedrock occurs and the bedrock features that are left are the speleogens. This process called speleogenesis is what leads to secondary formations or speleothems. The United States Code defines speleogens as "relief features on the walls, ceiling, and floor of any cave or