shale
UK: ʃeɪl | US: ʃeɪl
n. A fine-grained sedimentary rock formed by the compaction of clay, silt, or mud, often splitting into thin layers.
The word "shale" traces back to Old English scealu, meaning "shell" or "husk," reflecting its layered, flaky structure akin to peeling scales. By the 18th century, it became specifically associated with the rock type due to its tendency to split into thin, shell-like plates. The silent "e" is a common feature in English spelling but does not carry morphemic weight here.
The geologist collected samples of shale to study its fossil content.
Shale formations often contain natural gas deposits.
The riverbank eroded, exposing layers of ancient shale.
Fracking techniques are used to extract oil from shale rock.
The artist used shale slabs as a canvas for prehistoric carvings.