Concretion — sedimentary Identification & Properties | Geo-Gem
Concretion is a sedimentary. Concretions are hard, compact masses of mineral matter that form within sedimentary rock layers. They often have unusual shapes that can resemble fossils, eggs, or other objects. Form around a nucleus like a shell, bone, or mineral grain.
Explore Geo-Gem
- AI Rock & Mineral Identification — snap a photo and get an instant AI-powered ID
- Community Discoveries — browse finds from rockhounds around the world
- Field Guide — regional guides to rocks, minerals, and geology
- Rock & Mineral Database — comprehensive identification reference
- Marketplace — buy and sell specimens with verified collectors
- Rockhound Groups — join local clubs and online communities
- Events & Field Trips — upcoming geology events near you
- Leaderboard — top contributors in the community