sedimentary

Red jasper (likely iron-rich chert)

Microcrystalline quartz, SiO₂, colored by hematite/goethite

AI-generated identification · may be incorrect

Typically opaque brick-red to maroon with gray-white quartz patches, dull to slightly vitreous luster, and no visible cleavage; Mohs hardness about 6.5–7, specific gravity roughly 2.6. The pictured rounded, irregular specimen appears naturally weathered or lightly polished.

Identified September 13, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when silica-rich sediment or volcanic material is replaced/cemented by microcrystalline quartz and stained by iron oxides. Deposits range from Precambrian to younger ages and occur in banded iron formations, veins, and sedimentary beds.

Uses & applications

Used as an ornamental and lapidary stone for cabochons, carvings, beads, bookends, and tumbled specimens; rarely used as aggregate. Common material generally has modest collector value.

Geological facts

Its red color primarily reflects dispersed hematite rather than native metallic iron. Jasper is a variety of chert distinguished mainly by its opacity and abundant impurities.

Field identification & locations

Identify it by its opaque red body, fine-grained texture, quartz-like hardness, and lack of reaction to dilute acid; a steel file usually struggles to scratch it. Common sources include India, Madagascar, Brazil, Australia, South Africa, and the western United States.