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
Anthodite of a cactus or thistle plant. In its composite stalagmite form, frostwork may possess spiny limbs like a miniature fir tree. The term was first used by cave guides at Wind Cave in South Dakota, USA, during the 1890s to describe speleothems which looked like ice “frostwork”. Anthodite Anthodites (Greek ἄνθος "ánthos", “flower”, "-ode", adjectival combining form, "-ite" adjectival suffix) are speleothems (cave formations) composed of long needle-like crystals situated in clusters which radiate outward from a common base. The "needles" may be quill-like or feathery. Most anthodites are made of the mineral aragonite (a variety of calcium carbonate, CaCO),