sedimentary
Conglomerate
Conglomerate (clastic sedimentary rock type)
Hardness: 6-7 (on Mohs scale for most clasts); Color: Varied (usually gray, brown, or red depending on the matrix and clasts); Luster: Dull to earthy; Structure: Clastic with rounded fragments (>2mm diameter) embedded in a finer matrix.
- Hardness
- 6-7 (on Mohs scale for most clasts)
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (on Mohs scale for most clasts); Color: Varied (usually gray, brown, or red depending on the matrix and clasts); Luster: Dull to earthy; Structure: Clastic with rounded fragments (>2mm diameter) embedded in a finer matrix.
Formation & geological history
Formed through the lithification of rounded gravel and boulders. Typically found in high-energy environments like riverbeds, alluvial fans, or beaches where water action rounds the rock fragments over time; age ranges from Precambrian to Holocene.
Uses & applications
Mostly used in the construction industry as coarse aggregate for concrete, road base material, and fill. Occasionally used as ornamental stone if it contains attractive clasts (like puddingstone).
Geological facts
Conglomerate is often nicknamed 'puddingstone' because it looks like raisins or fruit in a pudding. It is an index rock for identifying ancient high-velocity water currents.
Field identification & locations
Identify in the field by looking for rounded, smooth pebbles of different rock types cemented together in a solid mass. It is commonly found in mountainous regions or along active/ancient coastal and riverine environments.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary