sedimentary

Tumbled brown jasper

Jasper, an opaque, microcrystalline variety of quartz (SiO₂), often colored by iron oxides

AI-generated identification · may be incorrect

Smooth, opaque brown stone with subtle mottling and a polished luster. Quartz has Mohs hardness 7 and a trigonal crystal structure; the microcrystalline texture gives no visible cleavage and a specific gravity near 2.6.

Identified October 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich fluids or sediments become silicified, with iron impurities producing brown colors. Jasper can occur in rocks of many geological ages; the specimen’s exact age and locality cannot be determined from the image.

Uses & applications

Used for beads, cabochons, carvings, and decorative objects; also collected as an inexpensive ornamental stone.

Geological facts

“Jasper” describes an opaque, patterned variety of chalcedony rather than a single precisely defined geological type.

Field identification & locations

Look for opacity, fine-grained texture, and hardness sufficient to scratch glass; iron-rich brown tones are common. Found worldwide, including in silica-rich sedimentary and volcanic settings.