sedimentary

Jasper

Jasper (Silica/Silicon Dioxide, SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown, dull green, earthy; Luster: Dull to greasy; Crystal Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.5-2.9.

Hardness: 6
Color: Reddish-brown, dull green, earthy
Luster: Dull to greasy

Identified April 12, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the accumulation of fine-grained silica in hydrothermal veins or sedimentary environments. Iron oxides often provide the reddish hues. This specimen appears to have a weathered outer surface with green and red mineral zones.

Uses & applications

Used primarily as decorative gemstones, in jewelry (cabochons), as an industrial abrasive, and for ornamental stone carvings.

Geological facts

Jasper is an opaque variety of chalcedony. It has been used by humans for thousands of years, including for making early stone tools due to its hardness and sharp edges when fractured.

Field identification & locations

Identify by its hardness (it will scratch glass), opaque nature, and smooth, curved (conchoidal) fracture lines on fresh surfaces. Often found in riverbeds or areas with volcanic activity.