sedimentary

Conglomerate

Hardness: variable depending on clasts (usually 6-7 if quartz-rich); Color: grey matrix with multicoloured rounded stones; Luster: dull/earthy; Structure: clastic; Cleavage: none; SG: 2.5-2.8

Hardness: variable depending on clasts (usually 6-7 if quartz-rich)
Color: grey matrix with multicoloured rounded stones
Luster: dull/earthy

Identified June 20, 2026More sedimentary →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: variable depending on clasts (usually 6-7 if quartz-rich); Color: grey matrix with multicoloured rounded stones; Luster: dull/earthy; Structure: clastic; Cleavage: none; SG: 2.5-2.8

Formation & geological history

Formed through the lithification of rounded gravel and boulders, typically in high-energy environments like riverbeds or alluvial fans.

Uses & applications

Used primarily in the construction industry as fill material or decorative building stone; occasionally used as an architectural veneer.

Geological facts

Conglomerates are often called 'puddingstones' because they look like raisins or nuts in a pudding. They record ancient river systems and shorelines.

Field identification & locations

Identify by looking for rounded rock fragments (clasts) larger than 2mm embedded in a finer-grained matrix. Look in ancient riverbeds or mountain bases.