Rock Identifier
Polished red jasper (Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides) — mineral
mineral

Polished red jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

AI-generated identification · may be incorrect

Typically Mohs hardness 6.5–7, opaque red to reddish-brown, vitreous to waxy luster, cryptocrystalline structure, and no visible cleavage; specific gravity about 2.5–2.9.

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Physical properties

Typically Mohs hardness 6.5–7, opaque red to reddish-brown, vitreous to waxy luster, cryptocrystalline structure, and no visible cleavage; specific gravity about 2.5–2.9.

Formation & geological history

Forms when silica-rich fluids cement or replace volcanic and sedimentary material, with iron producing the red color. Deposits commonly formed during Precambrian to younger geological periods.

Uses & applications

Used for cabochons, beads, carvings, ornaments, and polished specimens; occasionally used as decorative stone. This small tumbled piece has modest commercial value.

Geological facts

Jasper is not a single mineral but a rock composed chiefly of microscopic quartz. Dark patches may reflect iron-rich inclusions, brecciation, or included host material.

Field identification & locations

Identify it by its opaque brick-red color, smooth polish, hardness, and lack of cleavage; it should resist scratching by a steel blade. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.