sedimentary
Conglomerate
Clastic sedimentary rock (Conglomerate)
Hardness varies by clast composition (typically 7 for quartz clasts), color is variable including browns, tans, and grays, luster is dull to vitreous, poorly sorted rounded to sub-rounded pebbles and gravels cemented in a finer-grained matrix.
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Physical properties
Hardness varies by clast composition (typically 7 for quartz clasts), color is variable including browns, tans, and grays, luster is dull to vitreous, poorly sorted rounded to sub-rounded pebbles and gravels cemented in a finer-grained matrix.
Formation & geological history
Formed by the consolidation and cementation of gravel-sized and coarser clasts, typically in high-energy environments such as fast-flowing rivers, alluvial fans, or beach zones over millions of years.
Uses & applications
Used locally as aggregate in construction, road building, and occasionally as decorative stone or landscaping material.
Geological facts
Conglomerates provide direct evidence of past high-energy environments, as it takes considerable water velocity to transport and round pebble-sized clasts.
Field identification & locations
Easily identified in the field by its distinct 'natural concrete' appearance containing visibly rounded large pebbles or boulders embedded in a finer matrix. Found worldwide.
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