sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock)
Hardness varies (clasts 6-7 if quartz, matrix 3-5); color is a mix of browns, oranges, and grays; dull luster; clastic texture with rounded fragments >2mm in a fine-grained matrix.
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 varies (clasts 6-7 if quartz, matrix 3-5); color is a mix of browns, oranges, and grays; dull luster; clastic texture with rounded fragments >2mm in a fine-grained matrix.
Formation & geological history
Formed through the accumulation and subsequent lithification of rounded water-worn pebbles and gravel, typically in high-energy environments like riverbeds or alluvial fans.
Uses & applications
Used primarily in construction as coarse aggregate for concrete and roadbeds; decorative specimens are used in landscaping or as collector samples.
Geological facts
Commonly known as 'puddingstone' in certain regions (like Michigan or the UK) when the clasts contrast sharply with the matrix. It is a key indicator for geologists of past water flow.
Field identification & locations
Identify by looking for rounded rock fragments (clasts) cemented together; found globally in ancient riverbeds. For collectors, look for unique colors or varied pebble types.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Brown Sandstone (River Rock)
Arenite
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary