sedimentary

Rounded river stone (likely iron-stained sandstone or siltstone)

Indeterminate ferruginous sandstone/siltstone; composition cannot be confirmed from the image

AI-generated identification · may be incorrect

Opaque, brown to olive-gray, dull surface and smoothly rounded shape; likely quartz-rich with iron-oxide staining. Hardness and grain size cannot be determined visually; no distinct crystals or cleavage are visible.

Identified September 28, 2026More sedimentary →

Explore Rounded river stone (likely iron-stained sandstone or siltstone) 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: Rounded river stone (likely iron-stained sandstone or siltstone)
Scientific name: Indeterminate ferruginous sandstone/siltstone; composition cannot be confirmed from the image
Category: sedimentary
Identified: September 28, 2026
Method: Standard

AI Estimated Value

Usually under $1–$5 as an ordinary loose stone; value depends on verified identity, locality, or unusual features.

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 sedimentary rock rounded by prolonged water transport and abrasion, with brown coloration from iron oxides. Its geological age and exact formation environment are unknown.

Uses & applications

Primarily a natural collectible or decorative stone; no specific industrial use can be identified from the image.

Geological facts

The smooth, rounded outline is consistent with abrasion in a stream or on a beach, though handling or tumbling can also produce it.

Field identification & locations

Look for visible sand-sized grains, layering, and a gritty texture to distinguish sandstone from finer siltstone; a fresh broken surface would aid identification. Rounded stones occur in riverbeds, beaches, and glacial deposits worldwide.