mineral

Tumbled brown jasper or iron-rich chert

Microcrystalline quartz (SiO₂), likely limonite/goethite-stained

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; brown to golden-brown, opaque, with waxy to slightly vitreous luster and no visible cleavage. The rounded, glossy surface and dark porous-looking inclusions suggest natural weathering or tumbling; exact identification requires hardness and streak tests.

Identified September 9, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids replace or cement sediments, with iron oxides staining the quartz brown; commonly Precambrian to younger. The specimen appears water-worn or mechanically polished rather than freshly fractured.

Uses & applications

Used as a decorative stone, lapidary material, cabochons, beads, carvings, and collector specimens; durable jasper is occasionally used for small architectural accents.

Geological facts

Jasper is a variety of opaque chalcedony or chert, and its colors commonly result from hematite, goethite, or limonite. A glass-scratch test and white-streak test can help distinguish it from softer ironstone or slag.

Field identification & locations

Common in gravel beds and silica-rich volcanic or sedimentary terrains worldwide, especially Oregon, California, Arizona, Australia, and Brazil. It should leave no colored streak and should resist scratching by steel.