mineral

Tumbled brown jasper

Microcrystalline quartz/chalcedony (SiO₂), likely iron-stained jasper

AI-generated identification · may be incorrect

Opaque brown to olive-brown, mottled with lighter patches; vitreous to waxy polish, no visible cleavage, hardness about 6.5–7 Mohs, specific gravity roughly 2.6. Its rounded shape and glossy surface indicate tumbling and polishing.

Identified September 8, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich groundwater replaces or cements fine sediments, commonly incorporating iron oxides and other impurities that create brown coloration. Most specimens are Cenozoic or older, depending on the deposit.

Uses & applications

Used as an inexpensive ornamental stone, cabochon, bead, paperweight, and lapidary material; rarely used for aggregate or decorative stone.

Geological facts

Jasper is an opaque variety of chalcedony rather than a single mineral species; color and pattern depend on included hematite, goethite, clay, and other minerals.

Field identification & locations

Identify it by its opacity, fine-grained texture, earthy mottling, glassy polish, and inability to scratch with a steel knife (though testing can damage it). Common sources include India, Madagascar, Brazil, Australia, and the western United States.