: These minerals fill the pore spaces between sediment grains, acting as a "natural glue" that binds the mass into a hard rock.
Concretions grow from the inside out, typically starting with a nucleus. This process, known as diagenesis, occurs early in the burial history of sediment. concretion
: Groundwater rich in minerals (like calcite or iron) reaches a point of saturation and begins to solidify. : These minerals fill the pore spaces between
: Because concretions are harder than the surrounding rock, they often remain after the softer host rock has weathered away, creating dramatic landscape features. Common Types and Compositions known as diagenesis