Final answer:
Travertine is the chemically precipitated limestone that forms in caves or around hot springs, and it occurs when CaCO₃ precipitates from a solution of CaCO₃ in CO₂-rich water.
Step-by-step explanation:
The chemically precipitated limestone that forms in caves or around hot springs is termed travertine.
This type of limestone deposit forms when a saturated solution of CaCO₃ in CO₂-rich water rises toward Earth's surface or is otherwise heated, leading to the release of CO₂ gas as the water warms. This change causes CaCO₃ to precipitate from the solution.
Travertine is different from marble, which is a metamorphic rock formed from limestone under conditions of high heat and pressure, and gypsum, which is a mineral composed of calcium sulfate dihydrate. It is also not to be confused with chalk, which is a type of limestone composed primarily of the calcite skeletons of microscopic marine organisms.