sedimentary

Weathered iron-rich sandstone or ferruginous siltstone

Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)

AI-generated identification · may be incorrect

Hardness about 5–7; brown to reddish-brown, dull earthy luster, very fine to medium clastic texture, and no visible cleavage. The elongated, rounded shape appears naturally weathered or water-worn; exact identification requires a fresh surface and grain inspection.

Identified August 8, 2026More sedimentary →

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At a glance

Common name: Weathered iron-rich sandstone or ferruginous siltstone
Scientific name: Clastic sedimentary rock, likely quartz-rich sandstone cemented by iron oxides (Fe₂O₃/Fe₃O₄)
Category: sedimentary
Identified: August 8, 2026
Method: Standard

AI Estimated Value

About $1–$20 as an ordinary specimen; potentially $25–$75 if unusually shaped, locality-documented, or historically significant.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

Formation & geological history

Formed from compacted and cemented sand or silt, with iron-bearing groundwater producing the rusty coloration; age cannot be determined from the image. Such rocks form in terrestrial, river, floodplain, or shallow-marine sedimentary environments.

Uses & applications

Common ferruginous sandstone is used as building stone, paving, aggregate, and landscaping material; this individual piece has mainly decorative or educational value.

Geological facts

Iron oxides can strongly stain sandstone red, orange, or brown. Its smooth, flattened form may reflect prolonged stream abrasion or weathering along natural bedding planes.

Field identification & locations

Look for visible quartz grains, gritty texture, sedimentary layering, and a reddish streak or iron staining; a steel nail may scratch softer varieties. Common worldwide, especially in iron-rich sedimentary basins.