sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Brick red to deep brown-red; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Brick red to deep brown-red
Luster: Vitreous to dull

Identified June 28, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brick red to deep brown-red; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Formation & geological history

Formed via the deposition of silica from hydrothermal solutions or volcanic ash in sedimentary environments, where iron impurities provide the red pigmentation. It can occur in Precambrian to relatively modern geological formations.

Uses & applications

Used extensively for lapidary work, jewelry (cabochons, beads), decorative carvings, and as a popular collector's stone due to its ability to take a high polish.

Geological facts

Red Jasper has been used since antiquity as a 'stone of endurance' and was frequently used in Minoan Crete for seals. It is a variety of chalcedony that contains enough mineral impurities to make it opaque.

Field identification & locations

Identify by its deep red color, high hardness, and smooth, waxy feel when polished. It is commonly found in riverbeds, deserts, and volcanic regions worldwide, including South Africa, Brazil, and the USA.