chert

[churt]

noun

a compact rock consisting essentially of microcrystalline quartz.

Origin of chert

First recorded in 1670–80; origin uncertain

Related formschert·y, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for chert

Historical Examples of 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.
Narrative of a Second Expedition to the Shores of the Polar Sea
John Franklin
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
Peter Gray
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

British Dictionary definitions for chert

chert

noun

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

Derived Formscherty, adjective

Word Origin for chert

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].

chert in Science

chert

[chûrt]

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.