sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂), colored by hematite/goethite inclusions

AI-generated identification · may be incorrect

Typically hardness 6.5–7, opaque red-brown, with a dull to waxy luster and conchoidal fracture; no visible cleavage. Its dense, fine-grained texture and iron-oxide staining are characteristic.

Identified August 21, 2026More sedimentary →

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Physical properties

Typically hardness 6.5–7, opaque red-brown, with a dull to waxy luster and conchoidal fracture; no visible cleavage. Its dense, fine-grained texture and iron-oxide staining are characteristic.

Formation & geological history

Usually forms when silica-rich sediment or volcanic material is replaced and cemented, with iron oxides producing the red color. Deposits range from Precambrian to younger ages and commonly occur in banded iron formations, chert beds, and volcanic terrains.

Uses & applications

Used for beads, cabochons, carvings, ornamental stone, and lapidary work; massive material is occasionally used as a decorative aggregate.

Geological facts

Jasper is a variety of chalcedony or microcrystalline quartz, though “jasper” is also used broadly for opaque silica-rich rocks. The specimen’s rough, massive appearance is consistent with common red jasper rather than a transparent gemstone.

Field identification & locations

Identify by its opaque brick-red color, very fine grain, high density, and ability to scratch glass; a streak test is usually pale red-brown. Common sources include India, Madagascar, Brazil, South Africa, Australia, and the western United States.