sedimentary

Rounded gray pebble, likely quartz-rich river stone

Probably quartzite or quartz-rich sandstone; exact identification requires testing

AI-generated identification · may be incorrect

Smooth water-worn surface; pale gray, fine-grained, dull to weakly satin luster. Quartzite hardness is about 7 Mohs, while sandstone is typically 6–7; no visible cleavage or crystals. Specific gravity roughly 2.6–2.7.

Identified August 13, 2026More sedimentary →

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At a glance

Common name: Rounded gray pebble, likely quartz-rich river stone
Scientific name: Probably quartzite or quartz-rich sandstone; exact identification requires testing
Category: sedimentary
Identified: August 13, 2026
Method: Standard

AI Estimated Value

Usually $0.50–$5 for an ordinary pebble; approximately $5–$20 if unusually attractive, polished, or provenance-documented.

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 weathered from a quartz-rich parent rock and rounded by stream, beach, or tumbling action. Its precise geological age and formation environment cannot be determined from the photograph.

Uses & applications

Commonly collected as a polished or natural pebble and used decoratively in landscaping, crafts, and jewelry components; ordinary pieces have little commercial value.

Geological facts

The rounded outline and uniform gray color indicate abrasion and weathering rather than a fresh crystal face. A scratch test is more diagnostic than appearance alone.

Field identification & locations

Look for gritty grains, layering, or visible quartz: sandstone may show grains and weaker cohesion, whereas quartzite is dense and fractures through grains. Test whether it scratches glass (quartz-rich material usually does); avoid destructive testing if valuable.