sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz, SiO₂, colored mainly by hematite/goethite

AI-generated identification · may be incorrect

Typically opaque brick-red to brown with black or gray patches, dull to waxy luster, and conchoidal fracture; hardness about 6.5–7 Mohs, with no cleavage. The specimen appears rough and naturally weathered, possibly containing brecciated or iron-stained zones.

Identified September 3, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich sediments or volcanic fluids lithify and become impregnated with iron oxides; some varieties are Precambrian, while others are much younger. Common environments include banded iron formations, hydrothermal veins, and silicified sedimentary beds.

Uses & applications

Used as ornamental stone, cabochons, beads, carvings, tumbling material, and occasionally aggregate or decorative facing stone.

Geological facts

Its red color generally reflects hematite, while yellow-brown tones indicate goethite or limonite. Jasper is a variety of chalcedony/chert rather than a single mineral species.

Field identification & locations

Identify it by its opaque red coloration, very high hardness, lack of visible grains, and conchoidal breaks; it should scratch glass and resist a steel knife. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.