Final answer:
Chemically precipitated limestone that forms in caves or around hot springs is called calcite or aragonite, which are significant cave formations such as stalactites and stalagmites created over time by the deposition of calcium carbonate precipitated from CO2-rich water.
Step-by-step explanation:
The chemically precipitated limestone that forms in caves or around hot springs is called calcite or less commonly, its polymorph aragonite.
These formations occur when a saturated solution of calcium carbonate (CaCO3) in CO2-rich water comes towards Earth's surface or is heated, causing CO2 to be released and CaCO3 to precipitate out of solution. This process is particularly notable in cave formations such as stalactites and stalagmites, which are examples of calcium carbonate deposits that form spectacular natural structures within caves. Over time, drips of mineral-rich water slowly create these formations, as the minerals are deposited out of the water when CO2 escapes and the pH of the solution increases.
Such cave formations made of calcium carbonate are often observed in locations like Carlsbad Caverns, Mammoth Cave, and Luray Caverns. The solubility products and pH levels play significant roles in the transformation of dissolved calcium carbonate in rainwater back into solid calcite or aragonite in caves.