sedimentary
Brecciated stone pebble
Breccia
Hard, smooth, dark grey/black matrix with angular lighter grey/white clasts, dull to slightly waxy luster where polished
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Physical properties
Hard, smooth, dark grey/black matrix with angular lighter grey/white clasts, dull to slightly waxy luster where polished
Formation & geological history
Formed by the cementation of angular rock fragments. The smooth, rounded shape indicates it was likely shaped by water action, possibly in a riverbed or on a beach.
Uses & applications
Often used for decoration, landscaping, or collected by rockhounds
Geological facts
Breccia is distinguished from conglomerate by having angular clasts rather than rounded ones. The original fragments were broken by mechanical action before being cemented together.
Field identification & locations
Identify by the visible angular fragments held together by a fine-grained matrix. Often found in areas with a history of faulting or landslides, but rounded pebbles like this are typical of stream sediment.
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