argillaceous

English edit

From Latin argillaceus, from argilla (“clay”), from Ancient Greek ἄργιλλος (árgillos, “white clay, potter's earth”), from ἀργός (argós, “white”).

argillaceous (comparative more argillaceous, superlative most argillaceous)

(chiefly geology) pertaining to clay; made of, containing, or resembling clay
- 1864, Fitz-Hugh Ludlow, The Atlantic:
  […] natural colossi from two to five hundred feet high, done in argillaceous sandstone or a singular species of conglomerate, all of which owe their existence almost entirely to the agency of wind.
- 1994, Jeanette Winterson, Art & Lies, page 104:
  The gleam of the land is in its rocks, the fine-grained argillaceous rocks, here, not purple or grey, but green of living stone.

pertaining to clay