sedimentary

Tumbled brown jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂); exact variety cannot be confirmed from the image

AI-generated identification · may be incorrect

Smooth, opaque brown stone with subtle mottling and a waxy-to-vitreous polish. Quartz hardness is about 7 Mohs; trigonal crystal structure, but crystals are too fine to see and cleavage is absent.

Identified October 13, 2026More sedimentary →

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Physical properties

Smooth, opaque brown stone with subtle mottling and a waxy-to-vitreous polish. Quartz hardness is about 7 Mohs; trigonal crystal structure, but crystals are too fine to see and cleavage is absent.

Formation & geological history

Jasper forms when silica-rich fluids fill or replace rock, often incorporating iron oxides that produce brown and red colors. It occurs in settings spanning many geological ages; the specimen’s age and source cannot be determined visually.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; rarely used as an industrial silica source.

Geological facts

Jasper is valued for its opaque color patterns, unlike translucent varieties of chalcedony.

Field identification & locations

The even opacity, fine texture, and polished surface are consistent with jasper, though other brown chalcedony or quartz-rich rocks can look similar. Common sources include India, Brazil, Madagascar, and the western United States.