sedimentary

Conglomerate

Conglomerate (Sedimentary rock, clastic)

AI-generated identification · may be incorrect

Hardness: variable based on clasts (usually 6-7 if quartz-rich); Color: multicolored with grey, brown, tan, and blue hues; Luster: dull to earthy matrix with potentially vitreous clasts; Structure: clastic texture with rounded gravel-sized fragments; Cleavage: none.

Hardness: variable based on clasts (usually 6-7 if quartz-rich)
Color: multicolored with grey, brown, tan, and blue hues
Luster: dull to earthy matrix with potentially vitreous clasts

Identified July 4, 2026More sedimentary →

Explore Conglomerate in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed by the lithification of rounded gravel and boulders, typically in high-energy environments like riverbeds, alluvial fans, or beaches. This specimen shows significant rounding of internal fragments, indicating long-distance transport.

Uses & applications

Primarily used as coarse aggregate in the construction industry for concrete and road base; occasionally used as a decorative building stone or for landscape design.

Geological facts

Conglomerates are often called 'puddingstone' because they look like a fruit pudding. They are essential for geologists to track the flow of ancient rivers and determine the energy level of prehistoric environments.

Field identification & locations

Identify by looking for rounded, pebble-sized rocks 'glued' together by a finer-grained matrix. Found globally in ancient river basins and mountain-front deposits. Useful for mapping tectonic uplift.