[lahym-stohn] 
| 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. |
| lime·stone (līm'stōn') n. A common sedimentary rock consisting mostly of calcium carbonate, CaCO3, used as a building stone and in the manufacture of lime, carbon dioxide, and cement. |
Sedimentary rock formed primarily of calcium carbonate, often the skeletons of small marine organisms.
