chalk

Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed under the sea by the accumulation and lithification of hard parts of organisms, mostly microscopic plankton, which had settled to the sea floor. Chalk is common throughout Western Europe, where deposits underlie parts of France, and steep cliffs are often seen where they meet the sea in places such as the Dover cliffs on the Kent coast of the English Channel.

AI overview

Chalk is a soft, white, porous rock made of calcite that formed from the accumulated shells and hard parts of tiny sea creatures compressed over millions of years. It is commonly found in Western Europe, where it creates distinctive white cliffs, such as the famous Dover cliffs in England, where it meets the sea.

AI-generated from the Wikipedia summary — may contain errors.

Key facts

Rock.name: Chalk
Rock.type: Sedimentary
Rock.image: Seven Sisters 3.jpg
Rock.caption: Beachy Head is a part of the extensive Southern England Chalk Formation.
Rock.composition: Calcite (calcium carbonate)

via Wikipedia infobox

Wikidata facts

Image: Chalk (25800474082).jpg

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Commons category: Chalk
Commons gallery: Chalk
2022 Harmonized System Code: 250900
exact match: purl.obolibrary.org/obo/ENVO_00002054

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Article

9 sections

Contents

Description
Formation
Geology and geographic distribution
Mining
Uses
Previous uses
See also
References
Further reading

Chalk is mined for use in industry, such as for quicklime, bricks and builder's putty, and in agriculture, for raising pH in soils with high acidity. It is also used for "blackboard chalk" for writing and drawing on various types of surfaces, although these can also be manufactured from other carbonate-based minerals or gypsum.