mineral

Polished brown jasper or chalcedony

Microcrystalline quartz (SiO₂), likely iron-stained jasper/chalcedony

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque to slightly translucent brown with cream-gray banding, vitreous to waxy luster, and no visible cleavage. The smooth surface indicates tumbling or polishing; specific gravity is approximately 2.6.

Identified September 5, 2026More mineral →

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Physical properties

Formation & geological history

Silica-rich groundwater deposited microcrystalline quartz in fractures or cavities, with iron oxides producing the brown color; banding reflects changing fluids and impurities. Formation is typically Phanerozoic, though the host rock may be older.

Uses & applications

Used for cabochons, beads, carvings, decorative objects, and lapidary specimens; it has modest jewelry and collector value.

Geological facts

Jasper is opaque chalcedony colored by iron and other impurities, while more translucent material is classified as chalcedony or agate. Precise identification requires inspection of translucency, banding, and a scratch or hardness test.

Field identification & locations

Commonly found in volcanic and sedimentary terrains, including India, Madagascar, Brazil, Australia, and the western United States. Look for quartz-like hardness, conchoidal fracture, waxy luster, and resistance to scratching by steel.