sedimentary

Red shale (likely mudstone)

Iron-oxide-stained clay-rich shale; composition typically clay minerals and fine quartz, with hematite providing the red color

AI-generated identification · may be incorrect

Fine-grained, dull and earthy, reddish brown; shale splits into thin sheets, while mudstone breaks into blockier pieces. Typical hardness is about 2–4 Mohs; individual crystals are not visible.

Identified October 13, 2026More sedimentary →

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Physical properties

Fine-grained, dull and earthy, reddish brown; shale splits into thin sheets, while mudstone breaks into blockier pieces. Typical hardness is about 2–4 Mohs; individual crystals are not visible.

Formation & geological history

Forms as compacted mud and clay in quiet-water settings such as lakes, floodplains, or marine basins; the red hue develops from oxidation of iron during or after deposition. The age cannot be determined from the image.

Uses & applications

Used locally as fill or low-grade construction material; generally has little jewelry or collector value.

Geological facts

The pictured fragments are consistent with red shale or mudstone, but an image alone cannot distinguish them reliably.

Field identification & locations

Look for very fine grain and layered splitting; red iron staining is common in sedimentary rocks worldwide. Small loose fragments typically sell for $0–$5.