noun, noun which may take the genitive case particle 'no'
A fine-grained sedimentary rock that splits easily into layers. Used in geology and related fields.
Layers of shale extend across this region.
Natural gas can sometimes be extracted from shale.
The kanji 頁 (けつ) means 'page' or 'leaf', referring to the thin, leaf-like layers of shale, and 岩 (がん) means 'rock'. The reading is on'yomi.