Claystone

Part of speech: noun

Definitions

1. A sedimentary rock primarily formed from compressed clay particles that is known for its fine texture and is often utilized in pottery
2. A geological formation that consists largely of compacted clay, recognized for its softness and application in ceramic arts
3. A type of sedimentary rock characterized by a composition mainly of clay minerals, notable for its pliability and uses in both ceramics and construction

Etymology: "Claystone" is a plain compound, built from "clay" and "stone" with nothing hidden in it. "Clay" goes back to Old English "clæg", a sticky earth that could be shaped when wet and hardened when fired or dried, and "stone" is the ordinary Germanic word for a hard mineral mass. Put together, the name describes exactly what the rock is: a stone made mostly of compacted clay. The pairing follows a familiar English habit of naming rocks by their dominant material, as with "limestone" and "sandstone," which are formed from calcium carbonate and sand grains respectively. Claystone is the same kind of label, applied to a rock whose particles are fine enough that it feels soft and crumbles easily in the hand, which is why potters and ceramicists have long valued it as a source of workable material.

Synonyms: shale