mineral

Iron-rich rock fragment (likely limonite/goethite weathering material)

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and/or limonite (variable mixture)

AI-generated identification · may be incorrect

Rusty orange-brown, rough and porous with dark cavities; likely earthy to dull luster and low-to-moderate hardness (about 4–5.5 Mohs if goethite-rich). The image does not show enough detail to determine crystal structure or specific gravity reliably.

Identified October 11, 2026More mineral →

Explore Iron-rich rock fragment (likely limonite/goethite weathering material) 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: Iron-rich rock fragment (likely limonite/goethite weathering material)
Scientific name: Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and/or limonite (variable mixture)
Category: mineral
Identified: October 11, 2026
Method: Standard

AI Estimated Value

Usually under $1 as an ordinary fragment; a few dollars at most as a labeled teaching or display 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

Forms as iron-bearing minerals oxidize and weather, commonly producing ironstone or a rusty coating/concretion. Iron-rich weathering products are plausible near the reported Sierra Nevada foothills location, but the photograph alone cannot establish provenance or age.

Uses & applications

Iron oxides are important iron ores and are used as pigments; this small irregular fragment has little commercial or jewelry value, though it may be of personal interest.

Geological facts

Goethite and related iron oxides create many of the red, orange, and brown colors seen in soils and weathered rocks.

Field identification & locations

Look for a rusty streak, earthy texture, and possible attraction to a magnet if mixed with magnetite; a streak test and hardness check would help distinguish iron oxides from rusty metal or slag. The specimen could also be a corroded metal fragment, which cannot be ruled out from the image.