sedimentary
Conglomerate
Polymictic Conglomerate
Hardness: 6-7 (varies by clast type), Color: Reddish-brown matrix with white and grey clasts, Luster: Dull/Earthy, Structure: Clastic with rounded pebbles, Cleavage: None
Identified More sedimentary →
Explore Conglomerate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (varies by clast type), Color: Reddish-brown matrix with white and grey clasts, Luster: Dull/Earthy, Structure: Clastic with rounded pebbles, Cleavage: None
Formation & geological history
Formed by the lithification of rounded river or beach gravel and sand. The reddish color suggests iron oxide cementation in an oxidizing environment.
Uses & applications
Used as aggregate in construction, road fill, and sometimes as a decorative building stone or facing material.
Geological facts
The rounded shape of the pebbles within the rock indicates that they were transported over a long distance by water, which wore down their sharp edges.
Field identification & locations
Look for rounded, water-worn pebbles larger than 2mm embedded in a finer-grained matrix. Common in active river channels or ancient alluvial fans.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary