sedimentary or metamorphic

Weathered iron-rich stone, possibly chert or quartzite

Indeterminate; likely silica-rich rock with iron-oxide staining (SiO₂-dominant)

AI-generated identification · may be incorrect

Brown, gray, and rusty mottling; dull to slightly waxy luster; massive, fine-grained texture with no visible crystals or cleavage. Apparent hardness is roughly 6–7 Mohs if it scratches glass, but exact properties cannot be confirmed from the image.

Identified September 4, 2026More sedimentary or metamorphic →

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At a glance

Common name: Weathered iron-rich stone, possibly chert or quartzite
Scientific name: Indeterminate; likely silica-rich rock with iron-oxide staining (SiO₂-dominant)
Category: sedimentary or metamorphic
Identified: September 4, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 as an unidentified common cobble; potentially $10–$50 if distinctive, unusually attractive, or analytically identified as a collectible material.

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 a naturally weathered silica-rich cobble formed by sediment cementation or metamorphic recrystallization, with brown coloration from oxidation of iron-bearing minerals. Geological age and source cannot be determined visually.

Uses & applications

Usually a common field specimen, landscaping stone, or carving/tumbling material; not generally used commercially unless it proves to be high-quality chert, quartzite, or an ore-bearing rock.

Geological facts

The rounded shape indicates transport and abrasion by a river, beach, or glacial environment. Iron-oxide coatings commonly produce the ochre-brown surface colors.

Field identification & locations

Test hardness against glass, inspect a fresh broken surface for conchoidal fracture (chert) or granular quartz texture (quartzite), and check for a streak; a magnet may detect magnetite but not ordinary rust staining.