[ ahr-juh-lahyt ]
/ ˈɑr dʒəˌlaɪt /


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

Origin of argillite

1785–95; < Latin argill(a) argil + -ite1

Related forms

ar·gil·lit·ic [ahr-juh-lit-ik] /ˌɑr dʒəˈlɪt ɪk/, adjective Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for argillite

British Dictionary definitions for argillite


/ (ˈɑːdʒɪˌlaɪt) /


any argillaceous rock, esp a hardened mudstone

Derived Forms

argillitic (ˌɑːdʒɪˈlɪtɪk), adjective

Word Origin for argillite

C18: from Latin argilla clay (from Greek argillos) + -ite 1
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Science definitions for argillite


[ ärjə-līt′ ]

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.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.