calcium carbonate

noun

: a compound CaCO₃ found in nature as calcite and aragonite and in plant ashes, bones, and shells and used especially in making lime and Portland cement and as a gastric antacid

Examples of calcium carbonate in a Sentence

Recent Examples on the Web

Antacids generally contain aluminum hydroxide, calcium carbonate, sodium bicarbonate, or bismuth subsalicylate. —Ann Pietrangelo, Verywell Health, 4 Sep. 2025

Their bodies are made up of calcium carbonate and chitin, the same material that forms crab shells. —Laura Baisas Aug 20, Popular Science, 20 Aug. 2025

The main replacement is calcium carbonate, also known as chalk, which is much less opaque, and so food companies would need to use much more of it to get the same whitening effect. —Nicholas Florko, The Atlantic, 8 Aug. 2025

When parts of these trees decay, fungi and microbial communities turn the crystals into calcium carbonate, the primary ingredient that makes up limestone and chalk. —Jack Knudson, Discover Magazine, 7 July 2025

Word History

First Known Use

1868, in the meaning defined above

Rhymes for calcium carbonate

• borosilicate
• decontaminate
• deoxycholate
• deteriorate
• differentiate
• diisocyanate
• dinoflagellate
• excommunicate
• incapacitate
• insubordinate
• intercorporate
• interpenetrate

Kids Definition

calcium carbonate

noun

: a solid substance found in nature as limestone and marble and in plant ashes, bones, and shells and used especially in making lime and portland cement

Medical Definition

calcium carbonate

noun

: a calcium salt CaCO₃ that is found in limestone, chalk, marble, plant ashes, bones, and many shells, that is obtained also as a white precipitate by passing carbon dioxide into a suspension of calcium hydroxide in water, and that is used in dentifrices and in pharmaceuticals as an antacid and to supplement bodily calcium stores