sedimentary or metamorphic

Tumbled reddish-brown pebble, likely sandstone or iron-rich quartzite

Probable ferruginous sandstone (quartz-rich; SiO₂ with iron oxides), possibly quartzite

AI-generated identification · may be incorrect

Hardness approximately 6–7 Mohs; reddish-brown, fine-grained, dull to silky luster, rounded by abrasion, with no visible crystals or cleavage. The smooth surface and subtle layering suggest a sedimentary sandstone, while a very hard, compact texture would indicate quartzite.

Identified August 11, 2026More sedimentary or metamorphic →

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At a glance

Common name: Tumbled reddish-brown pebble, likely sandstone or iron-rich quartzite
Scientific name: Probable ferruginous sandstone (quartz-rich; SiO₂ with iron oxides), possibly quartzite
Category: sedimentary or metamorphic
Identified: August 11, 2026
Method: Standard

AI Estimated Value

About $1–$10 for a common pebble; up to $10–$30 if attractively polished or unusually patterned.

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

Sandstone formed from lithified quartz sand, commonly tens to hundreds of millions of years old; iron oxides produced the red-brown color. If quartzite, it formed when sandstone was metamorphosed under heat and pressure.

Uses & applications

Commonly collected as a polished or naturally rounded specimen and used decoratively; sandstone is also used as building stone and aggregate, while quartzite is used for countertops, paving, and construction.

Geological facts

The image alone cannot reliably distinguish sandstone from quartzite; a streak, hardness, and magnified grain test would help.

Field identification & locations

Likely found in streambeds, gravel deposits, beaches, or weathered sandstone/quartzite outcrops. It should scratch glass if quartz-rich; sandstone may show granular texture and crumble slightly at edges.