sedimentary

Red Jasper (Chert)

Silicon dioxide (SiO2) with iron oxide inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish-red; Luster: Dull to waxy; Crystal Structure: Microcrystalline/Trigonal (Cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to brownish-red
Luster: Dull to waxy

Identified April 26, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish-red; Luster: Dull to waxy; Crystal Structure: Microcrystalline/Trigonal (Cryptocrystalline); Cleavage: None; Specific Gravity: 2.58-2.91

Formation & geological history

Formed from the accumulation of silica-rich micro-organisms or chemical precipitation in sedimentary environments. High iron content provides the red pigment. It can also form during low-grade metamorphism or hydrothermally.

Uses & applications

Used primarily as decorative gemstones, lapidary cabochons, metaphysical healing stones, and historically for making sharp tools/arrowheads due to its conchoidal fracture.

Geological facts

Jasper has been used by ancient civilizations for seals and talismans. It was known as the 'rain bringer' in some Native American traditions. Red Jasper specifically is a common variety of Chalcedony.

Field identification & locations

Identify in the field by its opaque red color and smooth, glass-like conchoidal fractures (curved breaks). It is common in riverbeds and desert environments globally, notably in the USA, Brazil, and India.