sedimentary

Likely brown chert or jasper pebble

Microcrystalline quartz (SiO₂), possibly iron-stained chalcedony

AI-generated identification · may be incorrect

Small rounded brown specimen with a dull to slightly waxy luster and no visible crystals or cleavage. Quartz hardness is about 7 Mohs; specific gravity is approximately 2.6, though exact properties cannot be confirmed from the image.

Identified September 12, 2026More sedimentary →

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Physical properties

Formation & geological history

Chert forms when silica-rich fluids replace or cement sediment, commonly from microscopic marine organisms; jasper is an opaque, iron-rich variety. Formation ages range from Precambrian to recent, depending on the deposit.

Uses & applications

Commonly used for ornamental objects, beads, cabochons, and occasionally as a source of knappable stone; this small piece has minimal commercial value.

Geological facts

The brown color likely comes from iron oxides or hydroxides. A true identification would benefit from a closer image, translucency test, streak, and hardness test.

Field identification & locations

Look for a smooth conchoidal fracture, glassy or waxy surface, and inability to scratch with a steel knife; quartz should scratch glass. Common worldwide in gravel beds, stream deposits, and sedimentary formations.