sedimentary

Likely iron-rich chert or jasper pebble

Microcrystalline quartz (SiO₂), possibly iron-oxide-stained chert/jasper

AI-generated identification · may be incorrect

Small, rounded, opaque brown-and-ochre pebble with a waxy to dull luster; quartz hardness about 7 Mohs and no visible cleavage. The image does not resolve internal texture well enough for a certain identification.

Identified October 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Chert forms when silica-rich material precipitates or replaces sediment; iron oxides create brown, red, or yellow colors. Its age and exact formation environment cannot be determined from the photograph.

Uses & applications

Chert is used historically for tools and occasionally as a decorative stone; jasper-quality material may be polished for jewelry or collected.

Geological facts

Chert and jasper are varieties of microcrystalline quartz; their colors commonly reflect trace impurities, especially iron oxides.

Field identification & locations

Look for a hard, opaque stone with a smooth or waxy surface and conchoidal fracture; a scratch test or fresh broken surface would help distinguish it from other pebbles. Chert occurs widely in sedimentary rocks worldwide.