mineral

Tumbled jasper (likely brecciated or orbicular jasper)

Microcrystalline quartz (SiO₂) with iron-oxide and rock-fragment inclusions

AI-generated identification · may be incorrect

Opaque, mottled gray, brown, reddish-orange, and cream; typically dull to waxy luster and no visible crystals. Mohs hardness 6.5–7, conchoidal fracture, massive microcrystalline structure, and specific gravity about 2.55–2.70.

Identified August 21, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater replaces or cements volcanic sediments and breccias, with iron oxides producing red-brown coloration. Formation ages vary widely, commonly from Paleozoic to Cenozoic volcanic environments.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, ornaments, and lapidary inlay; durable but not generally a high-value gemstone.

Geological facts

The contrasting patches likely reflect brecciation, staining, or multiple silica-rich fluids rather than crystal growth. Tumbled surfaces can make field identification less certain.

Field identification & locations

Common in volcanic terrains and silica-rich gravels worldwide, including the western United States, Madagascar, Brazil, India, and Australia. Verify with a hardness test: it should scratch ordinary glass, while streak is usually white.