mineral

Tumbled brown stone, likely jasper or iron-rich chert

Microcrystalline quartz (SiO₂), possibly hematite/goethite-bearing jasper

AI-generated identification · may be incorrect

Opaque dark brown with tan mottling, smooth tumbled surface, and dull to slightly waxy luster; quartz-rich material is about Mohs 6.5–7, with no visible cleavage and likely specific gravity near 2.6.

Identified September 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement sediments, with iron oxides producing the brown coloration; commonly Precambrian to younger, depending on the source deposit.

Uses & applications

Used as a decorative stone, lapidary material, worry stone, or inexpensive cabochon; suitable for polishing but not typically high-value jewelry.

Geological facts

The mottled pattern is characteristic of jasper-like silica rocks, though a photograph cannot reliably distinguish jasper from chert or other iron-stained quartz materials.

Field identification & locations

Commonly found in gravel beds and volcanic or sedimentary terrains; field confirmation requires a glass-scratch test, strong streak comparison, and inspection of the freshly broken interior.