- a compact rock consisting essentially of microcrystalline quartz.
Origin of chert
First recorded in 1670–80; origin uncertain
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for chert
Seven specimens were of basalt and one each of chert and porphyry.The Topanga Culture Final Report on Excavations, 1948
A. E. Treganza
The chert has sometimes the appearance of calcedony, and is finely striped.
In the same limestone there are enormous beds of chert, agates, and carnelians.Canyons of the Colorado
J. W. Powell
Nodules and layers of "chert" (an impure kind of flint) occur in it, whilst in places it forms a hard rock called "firestone."Sea-Weeds, Shells and Fossils
Limestones lose their calcium carbonate by solution, leaving only clay with fragments of quartz or chert as impurities.The Economic Aspect of Geology
C. K. Leith
- a microcrystalline form of silica usually occurring as bands or layers of pebbles in sedimentary rock. Formula: SiO 2 . Varieties include flint, lyddite (Lydian stone)Also called: hornstone
C17: of obscure origin
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
Word Origin and History for chert
"flint-like quartz," 1670s, of unknown origin. Apparently "a local term, which has been taken into geological use" [OED].
Online Etymology Dictionary, © 2010 Douglas Harper
- A hard, brittle sedimentary rock consisting of microcrystalline quartz. It is often reddish-brown to green but can also occur in a variety of other colors, especially white, pink, brown, or black. Chert often contains impurities such as calcium, iron-oxide, or the remains of silica-rich organisms. It usually occurs as nodules in limestone and dolomite and has curved fractures.
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