mineral

Likely tumbled brown jasper or iron-rich chert

Microcrystalline quartz (SiO₂), probably colored by iron oxides

AI-generated identification · may be incorrect

Small polished/tumbled pebble, opaque brown to mustard-yellow with darker patches and a waxy-to-dull luster. Quartz hardness is about 7 Mohs; no visible cleavage, cryptocrystalline structure, and typical specific gravity near 2.6.

Identified August 13, 2026More mineral →

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Physical properties

Formation & geological history

Jasper and chert form when silica-rich fluids or sediments are replaced and cemented, with iron oxidation producing the brown-red coloration. Their ages vary widely, from Precambrian to relatively young sedimentary deposits.

Uses & applications

Used as inexpensive lapidary material for cabochons, beads, carvings, and tumbled stones; generally not used structurally.

Geological facts

The image is insufficient for a definitive species identification; similar pieces may be brown jasper, chert, petrified wood, or even a dyed stone. A glass-scratch test can help confirm quartz hardness, though it may damage the specimen.

Field identification & locations

Common worldwide, especially in sedimentary and volcanic terrains; inspect for uniform microcrystalline texture, lack of cleavage, and iron-rich mottling. A streak, specific-gravity, or microscopic test would improve identification.