Water on its endless cycle, absorbs large quantities of carbon dioxide as it condensates in the atmosphere to fall down again as rainwater.
In limestone areas when it rains, the rainwater will spread across the fields and sink into the cracks in limestone enlarging them by natural mechanic erosion and by the chemical reaction caused by carbon dioxide.
Limestone is formed mostly by calcium carbonate, which is dissolved by carbon dioxide saturated waters and originating calcium bicarbonate, and so becomes a soluble substance.
In its permeabilization process, as these waters reach the cave void, they create small drops that upon their release from the caves ceiling create all types of formations.
A part of these waters will naturally be evaporated, and thus diminishing substantially the amount of carbon dioxide initially existing. This operation will create and opposite chemical reaction, which means calcium bicarbonate will become calcium carbonate once again, and because this is solid it will hang from ceilings in cone shapes slowly growing throughout the ages under the name of stalactites. However if the drops fall at a regular cadency the chemical phenomenon can create formations from the ground which are known as stalagmites. Both formations can be joined as columns of astounding effects.
In the ceilings, because of narrow and long fissures through which water can drip during its permeabilization, great drapes of thin crystal filaments frequently grow using the same process described before.