sedimentary

Weathered ironstone concretion (possible hematite/goethite concretion)

Hematite–goethite-rich ferruginous concretion; primarily Fe₂O₃ and FeO(OH) in a silica/clay matrix

AI-generated identification · may be incorrect

Hardness about 5–6.5 Mohs; dark gray to brown with yellow-orange iron-oxide staining, dull to submetallic luster, earthy granular texture, and no obvious cleavage. The rounded shape and surface cavity suggest a naturally cemented concretion rather than a crystal.

Identified September 2, 2026More sedimentary →

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At a glance

Common name: Weathered ironstone concretion (possible hematite/goethite concretion)
Scientific name: Hematite–goethite-rich ferruginous concretion; primarily Fe₂O₃ and FeO(OH) in a silica/clay matrix
Category: sedimentary
Identified: September 2, 2026
Method: Standard

AI Estimated Value

Typically $2–$15 for a common hand specimen; roughly $20–$75 if locality-documented, unusually dense, or aesthetically distinctive.

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 when iron-bearing groundwater precipitated oxides and hydroxides around a nucleus within sediment, later rounded by weathering or transport. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used historically as iron ore and pigment; today it is mainly a teaching or collecting specimen. It has little jewelry or construction use unless unusually dense or attractive.

Geological facts

Hematite commonly produces red-brown streak, while goethite produces yellow-brown streak; a streak test is more diagnostic than surface color. The specimen does not show convincing meteorite features such as a fusion crust or regmaglypts.

Field identification & locations

Common in weathered sedimentary terrains, lateritic soils, and iron-rich gravels worldwide. Test streak on unglazed porcelain, magnetism, density, and a fresh broken surface; avoid acid testing unless necessary.