Conglomerate

Coarse-grained clastic sedimentary rock composed of rounded to subangular gravel-size clasts (> 2 mm in diameter) set in a finer-grained matrix of sand, silt, or clay, and cemented usually by calcium carbonate, iron oxide, silica, or hardened clay. Hardness varies depending on the clasts and cement. Color varies widely based on composition.

Formed by the accumulation and lithification of rounded rock fragments (gravel, pebbles, cobbles) transported by water, ice, or gravity, typically in high-energy environments like river channels, beaches, or alluvial fans. The rounding of the clasts indicates significant transport distance or abrasion before deposition.

Often used as a construction material, as aggregate for road building, or sometimes cut and polished for ornamental purposes if the matrix is strong enough.

Conglomerates are distinguished from breccias, which are composed of angular clasts. They often represent ancient riverbeds or shoreline deposits, providing valuable clues about past sedimentary environments.

Identified by its visible, rounded to subangular pebbles or cobbles embedded in a finer matrix. Common worldwide in areas with past or present high-energy sediment transport systems.