sedimentary

Jasper with Hematite inclusions

Silicon Dioxide (SiO2) with Ferric Oxide (Fe2O3)

Hardness: 6.5-7 on Mohs scale; Color: Mottled yellow-brown, tan, and dark brown; Luster: Dull to waxy; Structure: Microcrystalline (Cryptocrystalline); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Mottled yellow-brown, tan, and dark brown
Luster: Dull to waxy

Identified March 22, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in volcanic ash or sedimentary beds, where iron oxides like hematite or goethite create the dark splotches. This specimen appears weathered/tumbled, likely from a stream or alluvial deposit.

Uses & applications

Commonly used for lapidary work (cabochons), river rock landscaping, aquarium gravel, and as a semi-precious stone for metaphysical or decorative collecting.

Geological facts

Jasper has been used by humans for thousands of years to create tools and ornaments. Because it is an opaque variety of chalcedony, it gets its name from the Greek word 'iaspis', meaning spotted stone.

Field identification & locations

Identify in the field by its hardness (it will scratch glass but cannot be scratched by a steel knife) and its opaque, non-translucent nature even on thin edges. Commonly found in desert regions, riverbeds, and gravel pits.

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