sedimentary

Red jasper (iron-rich chert), possibly brecciated

Microcrystalline quartz/chalcedony (SiO₂) colored by hematite and goethite

AI-generated identification · may be incorrect

Typically Mohs 6.5–7; opaque red, burgundy, brown, and yellow-brown with earthy to waxy luster and no visible crystal faces. Conchoidal fracture is common; the irregular texture suggests brecciation or iron-rich inclusions.

Identified August 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich fluids or sediment cement microcrystalline quartz, with iron oxides producing the red coloration; some varieties develop through volcanic or hydrothermal replacement. Ages range from Precambrian to recent depending on locality.

Uses & applications

Used as ornamental stone, cabochons, beads, carvings, tumbling material, and decorative aggregate; historically used for tools and pigments.

Geological facts

The red color chiefly reflects hematite, while yellow-brown areas commonly contain goethite or limonite. Jasper is technically an opaque, impurity-rich variety of chert.

Field identification & locations

Common in iron-rich sedimentary and volcanic terrains worldwide, including India, Madagascar, Brazil, Australia, and the western United States. A steel file should not easily scratch it; a streak test may show a white to reddish-brown powder, but testing can damage the specimen.