mineral

Tumbled brown jasper (probable)

Microcrystalline quartz/chalcedony, SiO₂, with iron-oxide inclusions

AI-generated identification · may be incorrect

Opaque dark brown to olive-brown, smoothly polished, with a dull-to-waxy luster and irregular ochre patches. Quartz hardness is about 6.5–7 Mohs; no visible cleavage and typically conchoidal fracture; specific gravity about 2.6.

Identified August 15, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich fluids replace or cement volcanic or sedimentary material, with iron oxides producing the brown coloration. Most specimens are geologically ancient, commonly Paleozoic or younger, and this piece has been shaped and polished by tumbling.

Uses & applications

Used for cabochons, beads, carvings, polished stones, and ornamental objects; common tumbled material has modest collector value.

Geological facts

Jasper is an opaque variety of chalcedony rather than a single mineral species. The image could also represent brown agate or petrified wood, but it lacks diagnostic banding or wood grain.

Field identification & locations

Field identification relies on opacity, fine texture, hardness, and resistance to scratching by a steel blade; a glass-scratch test can support quartz content. Brown jasper occurs worldwide, including India, Madagascar, Brazil, Australia, and the western United States.