argillite

American  

[ahr-juh-lahyt] / ˈɑr dʒəˌlaɪt /

noun

1. any compact sedimentary rock composed mainly of clay materials; clay stone.

---

argillite British  

/ ˈɑːdʒɪˌlaɪt, ˌɑːdʒɪˈlɪtɪk /

noun

1. any argillaceous rock, esp a hardened mudstone

---

argillite Scientific  

/ är′jə-līt′ /

1. A highly compacted sedimentary or slightly metamorphic rock consisting primarily of particles of clay or silt. Argillite differs from mudstone in that it does not have the same fine laminations, and from shale and slate in that it is not fissile.

---

Other Word Forms

• argillitic
  adjective

Etymology

Origin of argillite

1785–95; < Latin argill ( a ) argil + -ite ¹

Example Sentences

Winding paths of decomposed granite descend into the garden, where loosely arranged vertical slabs of argillite rock — a “living wall” — create pockets for vegetation to grow and animals to inhabit.

From Los Angeles Times • Feb. 11, 2022

Their Wall Street curled out of sight into a jumbled black terminus of precariously perched argillite boulders and other worthless rock till feeding the McKinley River.

From The Guardian • Nov. 8, 2018

The rocks of the mountains, owing to their resistant character, are not worn away as rapidly as the plains formations with the result that great thicknesses of limestone and argillite tower above the plains.

From Glacier National Park [Montana] by Interior, United States Dept. of the

Slate is, as we know, merely a variety of argillite.

From Scientific American Supplement, No. 1157, March 5, 1898 by Various

Next above that lies twenty-two hundred feet of Grinnell argillite, or red shale, a dull rock of varying pinks which weathers many shades of red and purple, deepening in places almost to black.

From The Book of the National Parks by Yard, Robert Sterling