sedimentary

Tumbled jasper or chert pebble

Microcrystalline quartz (SiO₂), likely jasper/chert with iron-oxide staining

AI-generated identification · may be incorrect

Opaque olive-brown and cream, with a dull to slightly waxy luster and irregular reddish-brown patches. Quartz hardness is about 6.5–7 Mohs; no visible cleavage, fine cryptocrystalline structure, and typical specific gravity near 2.6.

Identified August 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Likely formed when silica replaced or cemented sedimentary material, with iron oxides producing the red-brown coloration; its exact geological age cannot be determined from the photograph. The rounded shape indicates natural stream abrasion or tumbling/polishing.

Uses & applications

Used as a lapidary material for cabochons, beads, carvings, and decorative stones; ordinary pebbles have little industrial value compared with higher-quality jasper.

Geological facts

The specimen’s matte, rounded surface and mixed opaque colors are consistent with jasper or chert, though the image cannot distinguish them confidently from weathered quartzite or iron-rich river rock.

Field identification & locations

Field identification: test for glass-scratching hardness, look for a dense opaque body, waxy fracture, and absence of obvious grains or cleavage. Common in gravel beds and silica-rich volcanic or sedimentary regions.