sedimentary

Conglomerate

Conglomerate (clastic sedimentary rock)

Hardness: variable (depends on clasts/matrix); Color: multi-colored with gray green and brownish-red inclusions; Luster: dull to earthy; Structure: clastic texture with rounded gravel-sized fragments.

Hardness: variable (depends on clasts/matrix)
Color: multi-colored with gray green and brownish-red inclusions
Luster: dull to earthy

Identified July 2, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in high-energy environments like riverbeds, alluvial fans, or beaches where water currents are strong enough to transport and round large stones. Over millions of years, these sediments are buried and lithified by a mineral cement.

Uses & applications

Primarily used as a decorative stone in landscaping and gardens, aggregate in construction, or as an interest piece for geology collectors.

Geological facts

Conglomerate is often called 'puddingstone' because it looks like raisins or fruit in a pudding. It indicates the presence of an ancient high-energy water source.

Field identification & locations

Identify by the presence of rounded pebbles (clasts) larger than 2mm embedded in a finer-grained matrix. Commonly found along old river drainages or glaciated regions.

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Cone-in-cone structure (Secondary Sedimentary Structure)

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Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

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Shale or Slaty Mudstone

Argillaceous sedimentary rock

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Sandstone

Arenite (primarily SiO2)

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