sedimentary

Ironstone concretion (possibly a pyrite-bearing concretion)

Iron-oxide-cemented sedimentary concretion; exact mineral composition cannot be confirmed from the photograph

AI-generated identification · may be incorrect

Rounded, brown-gray specimen with a fine-grained surface and branching cracks; likely dominated by iron oxides such as goethite or hematite, possibly with quartz or clay. Hardness and specific gravity cannot be determined visually; no distinct crystal structure is visible.

Identified October 3, 2026More sedimentary →

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At a glance

Common name: Ironstone concretion (possibly a pyrite-bearing concretion)
Scientific name: Iron-oxide-cemented sedimentary concretion; exact mineral composition cannot be confirmed from the photograph
Category: sedimentary
Identified: October 3, 2026
Method: Standard

AI Estimated Value

About $5–$30 for an ordinary, small ironstone concretion; confirmed provenance or unusual mineral content may increase value.

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

Concretions form as minerals precipitate and cement sediment around a nucleus, often before the surrounding sediment becomes rock. Their age and precise formation environment cannot be determined from the image.

Uses & applications

Primarily a geological or teaching collectible; iron-rich material may be of mineralogical interest, but this specimen is not identifiable as an ore from appearance alone.

Geological facts

The handwritten label appears to include a locality or specimen number, but it is not sufficiently legible to establish provenance.

Field identification & locations

Its rounded form and iron-stained, cracked surface are consistent with a concretion, though a closer examination or label transcription is needed for a specific identification. Such specimens occur in many sedimentary formations worldwide.