chert

[churt]

noun

1. a compact rock consisting essentially of microcrystalline quartz.

chert

/ 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)

chert

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.

Other Word Forms

• cherty adjective

Word History and Origins

Origin of chert¹

First recorded in 1670–80; origin uncertain

Word History and Origins

Origin of chert¹

C17: of obscure origin

Example Sentences

Early in the 1970s, a paleontologist working on the outskirts of an Indian village found small, bead-like fossils embedded in the gray chert dotting the surrounding fields.

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Anyone found hitting the pale, more recently formed chert stone is strongly discouraged because it splinters, making it hazardous and impossible to split successfully.

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They analyzed the projectile point and found it was made of Hozomeen chert, a sedimentary rock specific to the North Cascades.

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Made from chert and quartz pebbles, most measured less than 2 centimeters.

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Subsurface pressure and temperature effects cause changes in the composition and properties of rocks, and from these we reap flint, chert, loess, kaolin, granite and clay.

Read more on Nature