limestone

American  

[lahym-stohn] / ˈlaɪmˌstoʊn /

noun

1. a sedimentary rock consisting predominantly of calcium carbonate, varieties of which are formed from the skeletons of marine microorganisms and coral: used as a building stone and in the manufacture of lime.

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limestone British  

/ ˈlaɪmˌstəʊn /

noun

1. a sedimentary rock consisting mainly of calcium carbonate, deposited as the calcareous remains of marine animals or chemically precipitated from the sea: used as a building stone and in the manufacture of cement, lime, etc

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limestone Scientific  

/ līm′stōn′ /

1. A sedimentary rock consisting primarily of calcium carbonate, often in the form of the minerals calcite or aragonite, and sometimes with magnesium carbonate in the form of dolomite. Minor amounts of silica, feldspar, pyrite, and clay may also be present. Limestone can occur in many colors but is usually white, gray, or black. It forms either through the accumulation and compaction of fossil shells or other calcium-carbonate based marine organisms, such as coral, or through the chemical precipitation of calcium carbonate out of sea water.

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limestone Cultural  

1. Sedimentary rock formed primarily of calcium carbonate, often the skeletons of small marine organisms.

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Etymology

Origin of limestone

First recorded in 1515–25; lime ² + stone

Compare meaning

How does limestone compare to similar and commonly confused words? Explore the most common comparisons:

• limestone vs. travertine

Example Sentences

Every Maltese resident was to live within a 10-minute walk of green space, on an island composed largely of limestone, concrete, and the parking lot of a Lidl, that overall turns brown in the summer.

From Slate • Jun. 6, 2026

This isn’t a column about aggregate—my sandstone versus limestone hot takes will have to wait.

From Barron's • Jun. 5, 2026

The scheme, led by Durham County Council and the Heritage Coast Partnership, focused on restoring magnesian limestone grasslands between Nose's Point near Seaham and Blackhall Rocks.

From BBC • May 23, 2026

Most well-known fossil sites are found in rocks such as shale, sandstone, limestone, or volcanic ash.

From Science Daily • Apr. 23, 2026

There was a good quarry of limestone on the farm, and plenty of sand and cement had been found in one of the outhouses, so that all the materials for building were at hand.

From "Animal Farm: A Fairy Story" by George Orwell