metamorphic

Tumbled brown river stone

Likely weathered iron-rich basalt, greenstone, or other mafic metamorphic rock; exact identification requires testing

AI-generated identification · may be incorrect

Dark brown to gray mottling with subtle greenish areas and a dull-to-waxy luster; fine-grained, rounded, and polished by abrasion. Typical hardness is about 5–7 Mohs, with no visible cleavage and likely moderate-to-high density.

Identified August 16, 2026More metamorphic →

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At a glance

Common name: Tumbled brown river stone
Scientific name: Likely weathered iron-rich basalt, greenstone, or other mafic metamorphic rock; exact identification requires testing
Category: metamorphic
Identified: August 16, 2026
Method: Standard

AI Estimated Value

About $1–$10 as a common river stone or tumbled specimen; potentially $20–$100+ if verified as attractive jade or another 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

Probably formed from mafic volcanic rock and later altered or metamorphosed, then rounded by river or beach transport; its geological age cannot be determined from the photograph.

Uses & applications

Suitable as a decorative hand specimen, worry stone, landscaping stone, or craft material; it has little commercial value unless laboratory testing reveals a distinctive mineral such as jade.

Geological facts

The smooth shape and subdued surface are characteristic of prolonged natural water abrasion or tumbling. Brown coloration commonly reflects iron-oxide staining or weathering.

Field identification & locations

Look for a dense, fine-grained texture, absence of vesicles, and a streak or freshly broken surface; hardness, specific gravity, magnetism, and thin-section analysis would distinguish basalt, greenstone, and jade-like rocks. Commonly found in river gravels and glacial deposits.