sedimentary

Possible iron-rich nodule or weathered ironstone

Limonite/goethite-rich concretion; commonly represented as FeO(OH)·nH₂O with iron oxides

AI-generated identification · may be incorrect

Brown-orange, earthy to dull luster, irregular rounded surface, and no visible crystal faces or cleavage; estimated Mohs hardness 4–5.5, with moderate-to-high specific gravity and potentially a yellow-brown streak.

Identified August 17, 2026More sedimentary →

Explore Possible iron-rich nodule or weathered ironstone in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

At a glance

Common name: Possible iron-rich nodule or weathered ironstone
Scientific name: Limonite/goethite-rich concretion; commonly represented as FeO(OH)·nH₂O with iron oxides
Category: sedimentary
Identified: August 17, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an ordinary hand specimen; attractive, unusually dense, or locality-labeled pieces may sell for $10–$30.

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

Likely formed by oxidation and cementation of iron-bearing sediments or minerals near Earth’s surface; its precise age and locality cannot be determined from the image alone.

Uses & applications

Common ironstone has limited commercial value as low-grade iron ore, pigment, or a teaching/collecting specimen; it is generally unsuitable for jewelry or construction aggregate.

Geological facts

Limonite is not a single true mineral but a mixture of hydrated iron oxides, often dominated by goethite. Brown-orange coloration commonly reflects weathering in oxygen-rich environments.

Field identification & locations

Test for a yellow-brown streak on unglazed porcelain, moderate hardness, and attraction to a strong magnet if magnetite is present; the specimen may also feel unusually heavy. Common in soils, weathered rock, bog deposits, and sedimentary formations.