sedimentary

Conglomerate

Clastic sedimentary rock (Conglomerate)

Hardness: variable based on clasts (usually 6-7 if quartz-rich); Color: light tan/buff matrix with multicolored clasts; Luster: dull/earthy; Texture: coarse-grained with rounded clasts larger than 2mm.

Hardness: variable based on clasts (usually 6-7 if quartz-rich)
Color: light tan/buff matrix with multicolored clasts
Luster: dull/earthy

Identified July 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in high-energy environments like riverbeds, alluvial fans, or beaches where water velocity is strong enough to transport large pebbles. The rounded shape of clasts indicates long-distance transport. Geological age varies by site.

Uses & applications

Primarily used in construction as fill material, road base, and occasionally as decorative dimension stone if well-indurated and aesthetically pleasing.

Geological facts

Conglomerate is often called "puddingstone" because the rounded pebbles look like raisins in a pudding. It differs from Breccia, which contains sharp, angular fragments.

Field identification & locations

Identify by looking for rounded pebbles (clasts) naturally cemented together in a finer-grained matrix. Commonly found in ancient river channels or mountain base deposits.

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Sandstone

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