mineral

Tumbled brown jasper

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

AI-generated identification · may be incorrect

Typically hardness 6.5–7 Mohs, opaque brown, tan, gray, and rusty red, with a dull to waxy luster and no visible cleavage; dense, cryptocrystalline quartz. The rounded shape indicates mechanical tumbling or natural water abrasion.

Identified September 14, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids fill cavities, fractures, or sedimentary pores and later harden into chalcedony/jasper; iron oxidation produces the brown-red coloration. Individual material may range from Paleozoic to Cenozoic depending on locality.

Uses & applications

Used for cabochons, beads, carvings, polished stones, ornaments, and lapidary work; generally a decorative rather than high-value gemstone.

Geological facts

Jasper is an opaque variety of chalcedony, often containing hematite, goethite, clay, or volcanic fragments. Patterns and colors vary widely, making locality names common in the collecting trade.

Field identification & locations

Identify by its opaque, fine-grained appearance, glassy-to-waxy polish, absence of cleavage, and inability to scratch it with a steel knife; quartz or feldspar grains may be visible in brecciated varieties. Common worldwide, including India, Brazil, Madagascar, the United States, and Australia.