mineral

Red jasper (likely rough jasper/chert)

Microcrystalline quartz (SiO₂), commonly colored by iron oxides

AI-generated identification · may be incorrect

Opaque reddish-brown, earthy to weakly vitreous luster, massive with no visible crystals or cleavage; Mohs hardness about 6.5–7, conchoidal to uneven fracture, specific gravity roughly 2.5–2.7.

Identified August 9, 2026More mineral →

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Physical properties

Opaque reddish-brown, earthy to weakly vitreous luster, massive with no visible crystals or cleavage; Mohs hardness about 6.5–7, conchoidal to uneven fracture, specific gravity roughly 2.5–2.7.

Formation & geological history

Forms when silica-rich groundwater or volcanic fluids replace or cement sediment, with iron oxides producing the red color. It may range from Precambrian to relatively young and commonly occurs in volcanic or sedimentary environments.

Uses & applications

Used for cabochons, carvings, beads, tumbled stones, ornaments, and lapidary work; historically used for tools and small decorative objects.

Geological facts

Jasper is a variety of chalcedony or microcrystalline quartz, though trade names often include related iron-rich chert. Color patterns and brecciation can create attractive collector material.

Field identification & locations

Identify by its opaque red-brown color, fine grain, lack of cleavage, and resistance to scratching by steel; a quartz crystal or glass scratch test can help confirm hardness. Common worldwide, including India, Australia, Brazil, Madagascar, and the western United States.