sedimentary
Conglomerate
Conglomerate rock
Hardness varies by clast (typically Mohs 6-7 for quartz pebbles), variable color including browns, grays, and tans, dull luster, clastic texture with rounded gravel-sized fragments cemented together in a finer matrix, no distinct cleavage.
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Physical properties
Hardness varies by clast (typically Mohs 6-7 for quartz pebbles), variable color including browns, grays, and tans, dull luster, clastic texture with rounded gravel-sized fragments cemented together in a finer matrix, no distinct cleavage.
Formation & geological history
Formed by the consolidation and cementation of gravel and rounded rock fragments transported by high-energy environments like rivers, streams, or ocean beaches, often occurring over millions of years.
Uses & applications
Used mainly as crushed stone in construction, road building, and occasionally as an ornamental decorative stone or architectural facing.
Geological facts
Conglomerates are often referred to colloquially as 'puddingstone' due to their appearance resembling a pudding loaded with fruits and nuts.
Field identification & locations
Easily identified in the field by its distinct 'nature's concrete' appearance, consisting of large, rounded pebbles visibly cemented within a finer-grained matrix. Found worldwide in sedimentary basins.
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