sedimentary
Conglomerate
Conglomerate (Clastic Sedimentary Rock)
Hardness: 2-7 (variable based on clasts/matrix); Color: Brown, tan, grey; Luster: Dull/Earthy; Structure: Clastic, containing rounded pebbles (clasts) larger than 2mm embedded in a finer matrix.
- Hardness
- 2-7 (variable based on clasts/matrix)
- Color
- Brown, tan, grey
- Luster
- Dull/Earthy
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Physical properties
Hardness: 2-7 (variable based on clasts/matrix); Color: Brown, tan, grey; Luster: Dull/Earthy; Structure: Clastic, containing rounded pebbles (clasts) larger than 2mm embedded in a finer matrix.
Formation & geological history
Formed through the lithification of rounded gravel and pebbles, typically in high-energy environments like fast-moving rivers, alluvial fans, or beaches where water rounds the stones over time.
Uses & applications
Used primarily in the construction industry as coarse aggregate for concrete and road material; occasionally used as ornamental stone if well-cemented and colorful.
Geological facts
Conglomerates are often called 'puddingstone' because they look like raisins or nuts in a pudding. They are key indicators for geologists to locate ancient river channels.
Field identification & locations
Identify by looking for rounded, water-worn pebbles fused together by a natural mineral cement. Commonly found in areas with historic sedimentary basins or modern river beds.
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