sedimentary

Brecciated rock, likely polymict breccia

Polymict breccia; exact lithology cannot be determined from the image

AI-generated identification · may be incorrect

Angular light-gray clasts are cemented in a dark matrix, giving a coarse, fractured appearance. Mineral composition, hardness, luster, and crystal structure cannot be reliably identified from the photograph.

Identified October 4, 2026More sedimentary →

Explore Brecciated rock, likely polymict breccia in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Breccia forms when angular rock fragments accumulate and become cemented, often near faults, volcanic vents, or impact structures. Its age and formation environment are unknown from the image.

Uses & applications

Breccia is used as decorative stone and, when suitable, as crushed aggregate or building stone; this specimen is chiefly of collector interest.

Geological facts

The angular fragments distinguish breccia from conglomerate, which contains rounded clasts. A close-up or fresh surface would help identify the clasts and cement.

Field identification & locations

Look for sharp-edged fragments of different sizes embedded in a finer matrix. Breccias occur in fault zones, volcanic deposits, and impact structures worldwide.