sedimentary
Conglomerate
Clastic sedimentary rock (Conglomerate)
Hardness: 6-7 (based on quartz content); Color: Mottled brown, tan, and grey; Luster: Variable (earthy to waxy depending on clasts); Structure: Clastic with rounded pebbles (>2mm) in a finer matrix; Specific gravity: 2.6-2.8
- Hardness
- 6-7 (based on quartz content)
- Color
- Mottled brown, tan, and grey
- Luster
- Variable (earthy to waxy depending on clasts)
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6-7 (based on quartz content); Color: Mottled brown, tan, and grey; Luster: Variable (earthy to waxy depending on clasts); Structure: Clastic with rounded pebbles (>2mm) in a finer matrix; Specific gravity: 2.6-2.8
Formation & geological history
Formed by the lithification of rounded gravel and pebbles in high-energy environments like riverbeds, alluvial fans, or beaches. Geological age can range from Precambrian to Holocene.
Uses & applications
Used primarily as construction aggregate for concrete, road base, and occasionally as decorative facing stone for buildings or as garden ornaments.
Geological facts
Conglomerate is often nicknamed 'pudding stone' because the rounded pebbles look like fruit in a pudding. It is one of the few rocks that directly records the energy of ancient water systems.
Field identification & locations
Identify by looking for distinct, water-worn rounded stones (clasts) cemented within a finer-grained matrix. Found commonly near ancient or modern river deposits and coastlines.
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