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Chert (/ tʃ ɜːr t /) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, [1] the mineral form of silicon dioxide (SiO 2). [2] Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood.
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, [1] [2] categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.
Flint and chert are the most commonly knapped materials and are compact cryptocrystalline quartz. The difference between the two terms is colloquial , and flint can be seen as a variety of chert. In common usage, flint may refer more often to high quality material from chalky matrix (i.e. "chalk flint" as found in Britain) and chert refers to ...
A radiolarian chert is well-bedded, ... deep water sediments. ... are somewhat less sharp than flint. References External links. Radiolarian Chert and Ribbon ...
For example, concretions in sandstones or shales are commonly formed of a carbonate mineral such as calcite; those in limestones are commonly an amorphous or microcrystalline form of silica such as chert, flint, or jasper; while those in black shale may be composed of pyrite. [18]
On April 25, 2014, then-Mayor Dayne Walling and other officials toasted with glasses of water to celebrate switching from Detroit’s water system to the Flint River, part of a cost-cutting move ...
Cryptocrystalline or amorphous stone such as chert, flint, obsidian, and chalcedony, as well as other fine-grained stone material, such as rhyolite, felsite, and quartzite, were used as a source material for producing stone tools.
Flint residents used social media to post outrageous photos to show how bad the Flint water crisis really is.