sedimentary

Rounded weathered stone, likely quartz-rich sandstone or fine-grained volcanic rock

Indeterminate hand specimen; probable quartz–feldspar sandstone (SiO₂-rich)

AI-generated identification · may be incorrect

Tan-gray, opaque, dull earthy luster, fine-grained and strongly rounded from abrasion; likely hardness about 5–7 Mohs, with no visible cleavage or crystals. The image alone cannot reliably distinguish sandstone from a weathered fine-grained igneous pebble.

Identified September 2, 2026More sedimentary →

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At a glance

Common name: Rounded weathered stone, likely quartz-rich sandstone or fine-grained volcanic rock
Scientific name: Indeterminate hand specimen; probable quartz–feldspar sandstone (SiO₂-rich)
Category: sedimentary
Identified: September 2, 2026
Method: Standard

AI Estimated Value

$0–$5 as a common pebble; possibly $5–$20 if locally significant, unusually attractive, or polished.

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

Most likely a naturally water-worn cobble formed by stream or beach transport; if sandstone, its grains lithified from ancient sediment, commonly millions to hundreds of millions of years old. Exact age and origin require locality and testing.

Uses & applications

Primarily a curiosity, teaching specimen, or lapidary material; unsuitable for precise industrial identification from the photograph. If competent and attractive, it may be polished or used decoratively.

Geological facts

Its elongated, capsule-like shape and smooth surface indicate prolonged mechanical abrasion rather than crystal growth. Surface weathering obscures texture and may make a rock appear more uniform than it is.

Field identification & locations

Look for gritty sand grains, bedding, and acid-inert behavior for sandstone; a glassy fracture and quartz-rich grains suggest quartzite, while a uniformly crystalline texture suggests an igneous rock. Common in river gravels, beaches, and glacial deposits.