mineral

Polished jasper

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide impurities

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque reddish-brown and dark brown, with a waxy to vitreous polish and no visible cleavage. Its compact microcrystalline quartz structure commonly produces mottled or brecciated patterns and a specific gravity near 2.6.

Identified August 23, 2026More mineral →

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Physical properties

Formation & geological history

Jasper forms when silica-rich groundwater replaces or fills cavities in volcanic or sedimentary rocks, incorporating iron oxides that create red and brown colors. Deposits occur in rocks ranging from Precambrian to much younger geological ages.

Uses & applications

Used as tumbled stone, cabochons, carvings, beads, ornamental objects, and occasionally decorative tile or facing stone; it is generally a lapidary and collector material rather than a gemstone of high monetary value.

Geological facts

The specimen appears to be a smoothly tumbled or polished jasper, possibly brecciated or picture jasper, though exact variety cannot be confirmed from one photograph.

Field identification & locations

Identify jasper by its opacity, earthy red-brown coloration, fine grain, and lack of crystal faces; it does not typically fizz in dilute acid. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.