sedimentary

Shale and Pebble Fragment

Sedimentary Rock (Mudstone/Shale with Silica Pebble)

AI-generated identification · may be incorrect

Hardness: 3-7 (depending on mineral component). Color: Greyish-brown, dull dark grey. Luster: Dull, earthy. Structure: Fine-grained, laminated slate/shale fracture on upper specimen.

Hardness: 3-7 (depending on mineral component)
Color: Greyish-brown, dull dark grey
Luster: Dull, earthy

Identified July 26, 2026More sedimentary →

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Physical properties

Hardness: 3-7 (depending on mineral component). Color: Greyish-brown, dull dark grey. Luster: Dull, earthy. Structure: Fine-grained, laminated slate/shale fracture on upper specimen.

Formation & geological history

Formed by the compaction and cementation of muddy or clay-rich sediments in quiet-water environments such as lakes, river floodplains, or deep marine basins.

Uses & applications

Shale is used in civil engineering, brick production, and cement manufacturing. Small pebbles are commonly used in decorative landscaping and aggregate.

Geological facts

Shale is the most common sedimentary rock on Earth, accounting for over half of all sedimentary rocks found in the geological record.

Field identification & locations

Identified by its fine grain size and tendency to break into thin layers (fissility). Extremely common in river beds, road cuts, and sedimentary basins worldwide.