mineral

Tumbled brown jasper

Microcrystalline quartz (chalcedony), chiefly SiO₂, colored by iron oxides and other inclusions

AI-generated identification · may be incorrect

Opaque brown, tan, reddish, and dark mottled colors; waxy to glassy luster; hardness about 6.5–7 Mohs; no visible cleavage; cryptocrystalline quartz structure; specific gravity ~2.6. The smoothly rounded surface indicates tumbling or water-worn abrasion.

Identified September 9, 2026More mineral →

Explore Tumbled brown jasper in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Jasper forms when silica-rich groundwater replaces or fills cavities in volcanic or sedimentary materials, with iron oxides producing the brown-red coloration. Its precise geological age and locality cannot be determined from the photograph.

Uses & applications

Used for cabochons, beads, carvings, polished stones, lapidary ornaments, and inexpensive collectible specimens; occasionally used decoratively in aggregate or tiles.

Geological facts

Jasper is an opaque variety of chalcedony, unlike transparent crystalline quartz. Color patterns reflect impurities and replacement textures rather than distinct large crystals.

Field identification & locations

Identify it by its opaque appearance, fine-grained texture, strong resistance to scratching, and lack of cleavage; a steel file should not easily scratch it. Common sources include India, Madagascar, Brazil, Australia, Mexico, and the western United States.