sedimentary

Ironstone concretion (possible pyrite-bearing nodule)

Iron-oxide-rich concretion, chiefly goethite/hematite; composition cannot be confirmed from the image

AI-generated identification · may be incorrect

Small, rounded, bronze-gray nodule with a rough, faintly metallic-looking surface. Hardness and specific gravity cannot be judged reliably from the photograph; it may be dense and brittle, with no obvious cleavage.

Identified October 3, 2026More sedimentary →

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At a glance

Common name: Ironstone concretion (possible pyrite-bearing nodule)
Scientific name: Iron-oxide-rich concretion, chiefly goethite/hematite; composition cannot be confirmed from the image
Category: sedimentary
Identified: October 3, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common, small, unidentified nodule; more only if testing reveals an unusual or well-formed mineral specimen.

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

Iron-rich minerals can cement sediment into rounded concretions during burial and groundwater movement. The image does not establish its age; a find near London could plausibly be a transported or construction-fill specimen rather than local bedrock.

Uses & applications

Primarily a curiosity or teaching/collecting specimen; ironstone has also been used as iron ore and building stone.

Geological facts

A metallic sheen alone does not identify pyrite: iron oxides and other coatings can look similar, and a photograph cannot confirm mineral composition.

Field identification & locations

Look for a heavy feel and a brown-to-rusty streak, which support iron oxides; a dark green-black streak and brassy color would suggest pyrite instead. The reported London-area location does not uniquely identify it.