sedimentary

Conglomerate

Polymictic Conglomerate

Hardness: 6.5-7 (individual clasts); Color: Tan matrix with brown, orange, and grey pebbles; Luster: Dull/Earthy matrix with waxy clasts; Structure: Clastic; Texture: Coarse-grained rounded pebbles

Hardness: 6
Color: Tan matrix with brown, orange, and grey pebbles
Luster: Dull/Earthy matrix with waxy clasts

Identified July 18, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (individual clasts); Color: Tan matrix with brown, orange, and grey pebbles; Luster: Dull/Earthy matrix with waxy clasts; Structure: Clastic; Texture: Coarse-grained rounded pebbles

Formation & geological history

Formed in high-energy environments like riverbeds or alluvial fans where water currents were strong enough to transport large pebbles, eventually cementing them together with fine-grained sand and minerals.

Uses & applications

Primarily used as coarse aggregate in construction; can be used as decorative stone in landscaping or interior design when polished.

Geological facts

Often called 'puddingstone' in specific regions like the UK or Michigan, it acts as a record of ancient river paths. It differs from breccia because its fragments are rounded rather than angular.

Field identification & locations

Identify in the field by looking for rounded, water-worn stones embedded in a finer-grained matrix. Found globally in ancient river systems and shorelines.