sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂), colored by hematite/goethite; possibly brecciated jasper

AI-generated identification · may be incorrect

Typically Mohs 6.5–7, opaque, red to brown with black or yellow-brown patches, and a glassy to waxy luster when wet or polished. Quartz has no cleavage and a microcrystalline structure; specific gravity is about 2.6.

Identified August 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich sediment or volcanic material is cemented and replaced, with iron oxides producing the red coloration; brecciation may indicate later fracturing and cementation. Formation ages vary widely, from Precambrian to much younger deposits.

Uses & applications

Used for cabochons, beads, carvings, tumbled stones, and decorative objects; occasionally used as an ornamental building stone. Common specimens generally have modest commercial value.

Geological facts

Red jasper is a variety of chalcedony/chert rather than a single mineral species. Its color is mainly caused by finely dispersed hematite, while dark areas may contain manganese oxides or other rock fragments.

Field identification & locations

Common in iron-rich sedimentary and volcanic terrains worldwide, including India, Madagascar, Brazil, Australia, and the western United States. A glassy waxy surface, very high hardness, opaque red color, and inability to scratch it with a steel knife support identification; a streak test is often pale red-brown.