1. a small round grain consisting of concentric layers of calcium carbonate formed in shallow marine waters
Usage: geology
2. a sedimentary rock composed mainly of ooliths
Usage: geology

Examples

• The geologist examined the oolith under a microscope to study its layered structure.
• Ooliths form when calcium carbonate precipitates around sand grains in warm, shallow seas.
• The limestone quarry contained abundant oolith deposits from ancient marine environments.
• Each oolith showed distinct concentric rings when viewed in cross-section.
• The Bahama Banks are a modern example of where ooliths actively form today.
• Oolitic limestone made from compressed ooliths was used in many historic buildings.