metamorphic

Red jasper

Jasper, microcrystalline quartz (SiO₂) with iron-oxide impurities

AI-generated identification · may be incorrect

Typically opaque red to reddish-brown with black, gray, or cream patches; hardness about 6.5–7 Mohs, dull to vitreous luster, cryptocrystalline quartz, and no visible cleavage. The specimen appears rounded/tumbled and iron-rich.

Identified September 2, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when silica-rich groundwater cements or replaces sediments and volcanic material, with hematite/goethite producing the red color; deposits range from Precambrian to relatively young. Commonly associated with volcanic rocks and hydrothermal environments.

Uses & applications

Used for cabochons, beads, carvings, tumbling stones, ornaments, and minor decorative aggregate. It is popular as an inexpensive lapidary and collecting material.

Geological facts

Jasper is a variety of opaque chalcedony/quartz rather than a single strictly defined mineral species. Red coloration generally indicates finely disseminated iron oxides.

Field identification & locations

Identify it by its opacity, strong red coloration, fine-grained texture, and resistance to scratching; it should not fizz in dilute acid. Common sources include India, Brazil, Madagascar, Australia, South Africa, and the western United States.