sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite

AI-generated identification · may be incorrect

Typically hardness 6.5–7 Mohs, opaque red to reddish-brown, with a dull to waxy or slightly vitreous luster; massive, cryptocrystalline quartz has no visible cleavage. The specimen appears water-worn and may include pale quartz veins or surface weathering.

Identified September 2, 2026More sedimentary →

Explore Red jasper (likely iron-rich chert) in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Formation & geological history

Forms when silica-rich sediment or volcanic material is replaced and cemented by microcrystalline quartz, with iron oxides producing the red color. Jasper commonly formed during Precambrian to younger sedimentary and hydrothermal events.

Uses & applications

Used as ornamental stone, beads, cabochons, carvings, tumblestones, and decorative aggregate; durable pieces can be polished for jewelry.

Geological facts

Its red color is mainly due to finely dispersed hematite, not copper. Jasper is a broad gemological term rather than a single mineral species.

Field identification & locations

Identify it by its opaque red color, very fine texture, lack of cleavage, and ability to scratch glass; a streak test may be pale red-brown. Common worldwide, including India, Madagascar, Brazil, Australia, and the western United States.