sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron hydroxides

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs); Color: Mustard yellow to ochre; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Gravity: 2.58-2.91

Hardness: 6
Color: Mustard yellow to ochre
Luster: Dull to waxy

Identified February 19, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Mustard yellow to ochre; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Gravity: 2.58-2.91

Formation & geological history

Formed through the accumulation of silica-rich microfossils or volcanic ash that undergoes petrification. The yellow color comes from Goethite or other iron inclusions during the sedimentary process.

Uses & applications

Commonly used for lapidary work, cabochons for jewelry, small carvings, and as a decorative landscaping stone due to its durability and ability to take a high polish.

Geological facts

Jasper is an opaque variety of chalcedony. In ancient times, yellow jasper was often associated with protection and as a 'nurturing' stone in various folklore traditions.

Field identification & locations

Identify by its extreme hardness (cannot be scratched by a steel knife), smooth waxy feel, and conchoidal (shell-like) fracture patterns. Found in riverbeds or gravel deposits globally.