sedimentary

Weathered shale or mudstone outcrop

Fine-grained siliciclastic sedimentary rock, chiefly clay minerals, quartz, and feldspar

AI-generated identification · may be incorrect

Typically gray to greenish-gray, dull to earthy, very fine-grained, and weakly layered or fissile; hardness about 2–4 Mohs. Individual grains are mostly microscopic, with poor visible crystal structure and no prominent cleavage apart from bedding-related splitting.

Identified August 23, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when clay- and silt-sized sediment accumulated in quiet water, compacted, and cemented into mudstone or shale; the image likely shows a weathered, relatively young sedimentary exposure, but exact age requires mapping or laboratory analysis.

Uses & applications

Used locally as fill, low-grade aggregate, and feedstock for cement or bricks where composition is suitable; generally has little jewelry or collector value because it is soft, friable, and unstable when wet.

Geological facts

The loose gray surface material may be shale-derived colluvium rather than intact bedrock. Weathering commonly produces slopes prone to rilling, slumping, and landslides.

Field identification & locations

Identify it by fine texture, dull gray color, crumbly fragments, and thin bedding or fissility; a hand lens and dilute hydrochloric acid test help distinguish shale from calcareous mudstone. Common in sedimentary basins worldwide.