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

An NRG spokeswoman said that after a monitoring system malfunctioned during 2025, the Limestone plant was required to use EPA data-substitution rules, which resulted in reporting more emissions than were actually emitted.

From The Wall Street Journal • Feb. 26, 2026

Kathy helps run Limestone Presbyterian Church in Wilmington and one of her jobs is to put up a message with meaning on a sign at the front of the building.

From BBC • Nov. 3, 2024

In January, Uno, a female mountain lion often seen patrolling the mountains in Orange County, was killed after being struck by a vehicle on a road near the Limestone Canyon Nature Preserve.

From Los Angeles Times • Jun. 15, 2024

Limestone is common on Earth because life produces it en masse: the rock forms when shells and skeletons of ocean creatures, especially from coral reefs, pile up on the seafloor as the organisms die.

From National Geographic • Oct. 12, 2023

One day in June a letter came from a tennis coach from a college named Limestone in Gaffney, South Carolina.

From "Kaffir Boy: An Autobiography" by Mark Mathabane