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 brown to reddish-brown, earthy to waxy luster, cryptocrystalline quartz with no visible cleavage; specific gravity about 2.6.

Identified September 10, 2026More mineral →

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Physical properties

Typically Mohs hardness 6.5–7, opaque brown to reddish-brown, earthy to waxy luster, cryptocrystalline quartz with no visible cleavage; specific gravity about 2.6.

Formation & geological history

Forms when silica-rich fluids fill cavities or replace volcanic and sedimentary rocks, with iron oxides producing the brown color; individual pieces may range from Paleozoic to Cenozoic in age. Its smoothly rounded shape indicates natural water wear or human tumbling/polishing.

Uses & applications

Used for cabochons, beads, carvings, polished display stones, and inexpensive jewelry; occasionally used as decorative aggregate.

Geological facts

Jasper is a variety of opaque chalcedony rather than a single mineral species. Color and patterns vary widely according to iron, manganese, clay, and other inclusions.

Field identification & locations

Identify it by its opaque, fine-grained appearance, hardness sufficient to scratch glass, and lack of obvious crystals or cleavage; common sources include India, Brazil, Madagascar, Australia, and the western United States.