Flowstones

Part of speech: noun

Definitions

1. A type of mineral deposit that forms as water flows over surfaces, typically seen in caves or geological formations
2. It consists of layers of calcite or other minerals deposited by dripping or flowing water
3. These formations can create stunning visual effects in subterranean environments

Etymology: Flowstone is a plain English compound: "flow" joined to "stone," with no older history behind it. The term describes a sheet-like mineral crust, usually calcite, laid down by thin films of water running down a cave wall or floor. As the water evaporates or releases carbon dioxide, it leaves its dissolved mineral behind in smooth, rippling layers that look like frozen cascades. Speleologists use the term for this deposit specifically, and it is distinct from the stalactites and stalagmites that form from dripping water. Flowstone is a plural in the sense that the sentence is about several such formations; the singular, "flowstone," is the base noun. The word is recorded in caving and geology writing from the twentieth century, when the descriptive compound became standard among cave surveyors.