sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz, SiO₂, colored by iron oxides

AI-generated identification · may be incorrect

Hardness about 6.5–7 Mohs; opaque red, orange, brown, and gray with a dull to waxy luster and no visible cleavage. Its dense, fine-grained texture commonly produces a smooth conchoidal fracture when freshly broken.

Identified September 16, 2026More sedimentary →

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Physical properties

Formation & geological history

Usually forms when silica-rich sediment or volcanic-derived silica is cemented and stained by hematite or other iron oxides, commonly in Precambrian to younger sedimentary formations. The specimen appears naturally weathered or roughly broken.

Uses & applications

Used as an ornamental stone, cabochons, beads, carvings, lapidary material, and decorative aggregate; it has little value as a construction stone in small pieces.

Geological facts

Jasper is a variety of chert rather than a single mineral species, and its red color reflects oxidized iron. Patterns and colors can vary dramatically within one deposit.

Field identification & locations

Identify it by its opaque red coloration, very fine texture, heavy feel, and resistance to scratching; it should scratch glass but not be scratched by a steel knife. Common sources include India, Madagascar, Brazil, the United States, and Australia.