sedimentary

Polished river pebble, possibly chert or chalcedony

Likely microcrystalline quartz (SiO₂); exact identification is uncertain from the photograph

AI-generated identification · may be incorrect

Smooth, rounded and polished, with mottled gray, brown, cream, and dark patches and a subdued waxy-to-glassy sheen. If it is chert/chalcedony, hardness is about 6.5–7 Mohs; crystal structure is microscopic quartz, with no visible cleavage.

Identified October 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Probably a naturally rounded pebble shaped by water abrasion, then possibly polished. Chert forms as silica-rich sedimentary material; the pebble’s age and exact formation cannot be determined from appearance alone.

Uses & applications

Suitable for a collection, display, or craft use; chert has historically been used for tools, while chalcedony is used for beads and ornamental objects.

Geological facts

The handwritten label appears to say “...dolite ...nelian,” possibly “...dolite carnelian,” but the pebble’s muted, opaque appearance does not establish carnelian or another specific variety.

Field identification & locations

The reported location in southeast Texas is in a sedimentary region where transported pebbles are plausible; this image cannot confirm local bedrock origin. A scratch test and examination of a fresh edge for waxy translucence or conchoidal fracture could help distinguish chert/chalcedony from other stones.