mineral

Tumbled brown jasper

Microcrystalline quartz (chalcedony), SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, opaque reddish-brown to chocolate-brown, with a smooth waxy to glassy luster after tumbling; lacks visible crystals and cleavage, with conchoidal fracture. The rounded shape and polish indicate human processing.

Identified September 11, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich fluids replace or cement sediments and volcanic material, commonly incorporating iron oxides; deposits range from Precambrian to younger Phanerozoic ages. The exact variety and locality cannot be determined from the photograph.

Uses & applications

Used as inexpensive cabochons, beads, carvings, worry stones, and decorative objects; also collected for its color and pattern. It has little industrial value compared with ordinary quartz.

Geological facts

Brown jasper is a variety of opaque chalcedony rather than a single formally defined mineral species. Its color commonly comes from hematite or goethite inclusions.

Field identification & locations

Identify it by its opaque earthy color, very fine texture, waxy polish, and hardness sufficient to scratch ordinary glass; it should not fizz in dilute acid. Common sources include India, Madagascar, Brazil, Australia, and the western United States.