sedimentary

Jasper (Chert)

Silicon Dioxide (SiO2) with iron oxide impurities

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Yellowish-brown (limonitic); Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Yellowish-brown (limonitic)
Luster: Dull to waxy

Identified June 26, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Yellowish-brown (limonitic); Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed by the precipitation of silica from groundwater or in marine environments, often as hydrothermal deposits or within sedimentary beds. Its color comes from iron oxide inclusions.

Uses & applications

Used for lapidary work, jewelry (cabochons), river rock landscaping, and as a durable construction aggregate. Historically used for stone tools.

Geological facts

Yellow jasper is often associated with the solar plexus chakra in metaphysical beliefs. Because of its hardness, it is frequently found as rounded river pebbles after long-term erosion.

Field identification & locations

Identify by its smooth, waxy surface when wet, characteristic yellowish-tan-brown color, and inability to be scratched by a steel knife. Commonly found in riverbeds and gravel pits.