mineral

Polished iron-rich river pebble

Likely limonite/goethite-bearing quartzite or ironstone; exact identification requires testing

AI-generated identification · may be incorrect

Dark reddish-brown, earthy to submetallic luster, rounded and naturally tumbled; likely hardness about 5–7 depending on quartz content, with no obvious cleavage and variable specific gravity (~2.6–4.0).

Identified September 4, 2026More mineral →

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At a glance

Common name: Polished iron-rich river pebble
Scientific name: Likely limonite/goethite-bearing quartzite or ironstone; exact identification requires testing
Category: mineral
Identified: September 4, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as a common pebble; perhaps $10–$30 if unusually attractive, locally notable, or confirmed as a rarer iron-rich 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

Probably formed from silica-rich rock containing iron oxides/hydroxides, then weathered and rounded by stream or beach transport; age cannot be determined from the image.

Uses & applications

Primarily a decorative or collecting specimen; iron-rich stone may be used as pigment or aggregate, but this individual has little industrial value.

Geological facts

Brown-red coloration commonly comes from hematite, goethite, or limonite coatings and staining. The smooth surface appears naturally water-worn rather than deliberately cut.

Field identification & locations

Identify in the field by its rounded shape, rusty streak or coating, and possible attraction to a strong magnet if magnetite is present; a white streak and hardness test can help distinguish quartzite from softer ironstone. Common in gravel beds, beaches, and weathered iron-bearing formations.