chert

American  

[churt] / tʃɜrt /

noun

1. a compact rock consisting essentially of microcrystalline quartz.

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chert British  

/ tʃɜːt /

noun

1. Also called: hornstone.  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)

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chert Scientific  

/ chûrt /

1. 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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Other Word Forms

Derived Forms

• cherty
  adjective

Etymology

Origin of chert

First recorded in 1670–80; origin uncertain

Example Sentences

Chert is another common rock formed from these types of sediment.

From Textbooks • Jan. 1, 2017

Chert can also form biochemically and is discussed in the Biochemical subsection.

From Textbooks • Jan. 1, 2017

In 1920 the great Gide breathlessly read Chert at a sitting, declared it had "not one weakness, not one redundancy, nothing commonplace."

From Time Magazine Archive

Chert or flint pebbles for tube-mills are supplied mainly from the extensive deposits on the French and Danish coasts.

From The Economic Aspect of Geology by Leith, C. K. (Charles Kenneth)

Chert or flint constitutes grinding pebbles and tube-mill linings, and is also ground up for abrasives.

From The Economic Aspect of Geology by Leith, C. K. (Charles Kenneth)