mineral

Polished/tumbled brown jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7; opaque brown, rust-orange, and black coloration; waxy to dull luster; cryptocrystalline quartz with no visible cleavage and conchoidal fracture. The smooth rounded shape indicates tumbling or polishing.

Identified August 19, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater fills cavities or replaces volcanic and sedimentary rock, with iron and manganese oxides producing the dark mottling; deposits range from Precambrian to Cenozoic. Common sources include India, Madagascar, Brazil, Indonesia, and the western United States.

Uses & applications

Used for cabochons, beads, carvings, worry stones, and ornamental objects; occasionally used as decorative aggregate. It has modest value unless the pattern, polish, or locality is exceptional.

Geological facts

Jasper is a variety of opaque chalcedony rather than a single mineral species. Brown varieties may be marketed as picture jasper, iron jasper, or coffee jasper, though trade names are inconsistent.

Field identification & locations

Identify it by its opaque earthy pattern, glassy-to-waxy surface, lack of cleavage, and ability to scratch ordinary glass; it is not metallic and should not show obvious crystal faces. Exact variety cannot be confirmed from the photograph alone.