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

Tumbled 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 brick-red to reddish-brown, with a waxy to glassy luster; cryptocrystalline quartz has no visible cleavage and conchoidal fracture. The rounded, glossy form indicates tumbling and polishing.

Identified More mineral
Explore Tumbled red jasper in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

Physical properties

Typically Mohs hardness 6.5–7, opaque brick-red to reddish-brown, with a waxy to glassy luster; cryptocrystalline quartz has no visible cleavage and conchoidal fracture. The rounded, glossy form indicates tumbling and polishing.

Formation & geological history

Forms when silica-rich groundwater replaces or fills cavities and fractures in volcanic or sedimentary rocks, with iron producing the red color; deposits range from Precambrian to younger ages. Common sources include India, Madagascar, Brazil, Australia, and the western United States.

Uses & applications

Used for beads, cabochons, carvings, polished stones, and lapidary décor; historically used for tools and ornamental objects. Common tumbled pieces generally have modest collector value.

Geological facts

Jasper is a variety of chalcedony or microcrystalline quartz, though the term is often used broadly for opaque silica-rich rocks. Color intensity and patterns depend on hematite, goethite, and other iron minerals.

Field identification & locations

Identify by its opaque red-brown color, very fine texture, hardness, and lack of cleavage; it should scratch glass but not be scratched by a steel blade. The specimen appears commercially tumbled rather than naturally rounded.