sedimentary
Conglomerate
Conglomerate (Sedimentary rock, clastic)
Hardness: variable based on clasts (usually 6-7 if quartz-rich); Color: multicolored with grey, brown, tan, and blue hues; Luster: dull to earthy matrix with potentially vitreous clasts; Structure: clastic texture with rounded gravel-sized fragments; Cleavage: none.
- Hardness
- variable based on clasts (usually 6-7 if quartz-rich)
- Color
- multicolored with grey, brown, tan, and blue hues
- Luster
- dull to earthy matrix with potentially vitreous clasts
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: variable based on clasts (usually 6-7 if quartz-rich); Color: multicolored with grey, brown, tan, and blue hues; Luster: dull to earthy matrix with potentially vitreous clasts; Structure: clastic texture with rounded gravel-sized fragments; Cleavage: none.
Formation & geological history
Formed by the lithification of rounded gravel and boulders, typically in high-energy environments like riverbeds, alluvial fans, or beaches. This specimen shows significant rounding of internal fragments, indicating long-distance transport.
Uses & applications
Primarily used as coarse aggregate in the construction industry for concrete and road base; occasionally used as a decorative building stone or for landscape design.
Geological facts
Conglomerates are often called 'puddingstone' because they look like a fruit pudding. They are essential for geologists to track the flow of ancient rivers and determine the energy level of prehistoric environments.
Field identification & locations
Identify by looking for rounded, pebble-sized rocks 'glued' together by a finer-grained matrix. Found globally in ancient river basins and mountain-front deposits. Useful for mapping tectonic uplift.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary