A sedimentary rock and a variety of quartz made of extremely fine-grained, or cryptocrystalline, silica, also called chalcedony. The silica might be of organic origin, such as from the internal struct [..]

A cryptocrystalline form of quartz, microscopically granular. Occurs as nodules and as thin, continuous layers. Duller, less waxy luster than

"flint-like quartz," 1670s, of unknown origin. Apparently "a local term, which has been taken into geological use" [OED].

Fine-grained, usually dark-colored sedimentary rock of silica-rich composition.

A fine-grained sedimentary rock, similar to flint, that is white, pinkish, brown, gray, or blue-gray in color. In antiquity, chert was one of the universally preferred materials for making stone tools [..]

hard and dense sedimentary rock, light gray to dark gray (flint), composed of quartz crystals and silica derived from marine fossils. Usually found in limestone nodules.

A cryptocrystalline form of quartz, microscopically granular. Occurs as nodules and as thin, continuous layers. Duller, less waxy luster than chalcedony. Occurs in limestone, dolostone, and mudstones. [..]

Very fine grained silica (SiO2

A cryptocrystalline form of quartz, microscopically granular. Occurs as nodules and as thin, continuous layers. Duller, less waxy luster than chalcedony. Occurs in limestone, dolostone, and mudstones.

a hard flinty rock composed mainly of siliceous microfossils

(n) variety of silica containing microcrystalline quartz

A very fine-grained sedimentary rock

A hard variety of sedimentary rock, similar to flint. It breaks in a predictable fashion which made it highly desirable for prehistoric toolmakers.

A very fine-grained sedimentary rock made of quartz. Usually made of millions of globular siliceous skeletons of tiny marine plankton called radiolarians. Black chert is called flint.

A sedimentary rock composed of extremely fine-grained quarts, formed by organic or inorganic precipitation or by replacement. Flint and jasper are varieties of chert. Chockstone A rock or boulder wedged into a narrow canyon.

A very fine-grained rock formed in ancient ocean sediments. It often has a semi glossy finish and is usually white, pinkish, brown, gray, or blue gray in color. It can be shaped into arrowheads by chipping. It has often been called flint, but true flint is found in chalk deposits and is a distinctive blackish color.

A fine-grained sedimentary rock rich in quartz and usually light in colour. Chert is similar to flint, and was often used in the manufacture of stone tools.

A compact cryptocrystalline or microcrystalline variety of quartz originating from a sedimentary context.

sedimentary rock that is ultra–fine grained and composed almost entirely of silica. May be of organic or inorganic origin.

smooth form of black quartz chimera

Fine grained quartz rock usually occurring as thin layers in sedimentary sequences.

A type of stone similar to flint

A type of fine-grained, silica-rich rock often found in limestone. Native Americans shaped chert by carefully striking it with stone or bone hammers.

see lithic materials

Rock similar to flint. It can be knapped but is mostly of lower quality. Chert is usually found in shades of white, pink, brown and grey. Lots of Chert found in the Lower Thames Valley, UK

a very fine grained rock formed in ancient ocean sediments. It often has a semi-glassy finish and is usually white, pinkish, brown, gray or blue-gray in colour. It can be shaped into arrowheads by chipping. It has often been called flint, but true flint is found in chalk deposits and is a distinctive blackish colour.

(geology,uncountable) Massive, usually dull-colored and opaque, quartzite, hornstone, impure chalcedony, or other flint-like mineral. (countable) A flint-like tool made from chert.