sedimentary

Red Jasper (Chert)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Brick red to brownish-red; Luster: Vitreous to waxy; Structure: Microcrystalline/Cryptocrystalline quartz; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

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

Identified May 21, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in sedimentary environments or as primary deposits in volcanic rock. The red color is typically caused by iron (hematite) inclusions. It can span a wide range of geological ages from the Precambrian to more recent eras.

Uses & applications

Used primarily as a gemstone for jewelry, decorative carvings, and ornaments. Historically used for making tools due to its conchoidal fracture which creates sharp edges.

Geological facts

Jasper has been used as a gemstone since antiquity and is mentioned in many historical texts, including the Bible. It is often referred to as the 'Supreme Nurturer' in metaphysical circles.

Field identification & locations

Identify in the field by its opaque nature (unlike agate which is translucent), its smooth conchoidal fracture surfaces, and high hardness (will scratch glass). Commonly found in riverbeds, deserts, and areas with volcanic activity.