sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock type)

AI-generated identification · may be incorrect

Hardness: 6-7 (on Mohs scale for most clasts); Color: Varied (usually gray, brown, or red depending on the matrix and clasts); Luster: Dull to earthy; Structure: Clastic with rounded fragments (>2mm diameter) embedded in a finer matrix.

Hardness: 6-7 (on Mohs scale for most clasts)
Luster: Dull to earthy

Identified March 18, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the lithification of rounded gravel and boulders. Typically found in high-energy environments like riverbeds, alluvial fans, or beaches where water action rounds the rock fragments over time; age ranges from Precambrian to Holocene.

Uses & applications

Mostly used in the construction industry as coarse aggregate for concrete, road base material, and fill. Occasionally used as ornamental stone if it contains attractive clasts (like puddingstone).

Geological facts

Conglomerate is often nicknamed 'puddingstone' because it looks like raisins or fruit in a pudding. It is an index rock for identifying ancient high-velocity water currents.

Field identification & locations

Identify in the field by looking for rounded, smooth pebbles of different rock types cemented together in a solid mass. It is commonly found in mountainous regions or along active/ancient coastal and riverine environments.