sedimentary

Breccia

Hardness: 3-7 (variable based on clasts); Color: Tan, gray, brown, or multicoloured; Luster: Dull to earthy; Structure: Clastic with angular fragments over 2mm; Cleavage: None

Hardness: 3-7 (variable based on clasts)
Color: Tan, gray, brown, or multicoloured
Luster: Dull to earthy

Identified May 24, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3-7 (variable based on clasts); Color: Tan, gray, brown, or multicoloured; Luster: Dull to earthy; Structure: Clastic with angular fragments over 2mm; Cleavage: None

Formation & geological history

Formed by the accumulation of angular rock fragments or mineral debris. Found in fault zones (fault breccia), at the base of cliffs (talus), or from volcanic activity (volcanic breccia). Any geological age.

Uses & applications

Used primarily as road base, construction aggregate, and occasionally as architectural stone or decorative interior finish when the pattern is attractive.

Geological facts

The word 'breccia' comes from the Italian word for 'loose gravel' or 'stone made of gravel'. Unlike conglomerate, the fragments are angular, indicating they have not traveled far from their source.

Field identification & locations

Look for sharp, angular rock fragments cemented in a finer-grained matrix. Often found in tectonic zones or areas of high-energy debris flows. Collectors look for high contrast between fragments and matrix.