Sedimentary

Jasper with Quartz (Agate/Jasper mix)

Silicon Dioxide (SiO2) with iron oxide inclusions

Hardness: 6.5-7 (Mohs scale); Color: Cream, tan, and reddish-brown; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Cream, tan, and reddish-brown
Luster: Vitreous to waxy

Identified February 20, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the deposition of silica-rich fluids in volcanic rock cavities or sedimentary environments. The reddish-brown colors are due to iron ochre (hematite or goethite) inclusions. Age varies by locality, ranging from millions to hundreds of millions of years old.

Uses & applications

Used primarily in lapidary arts for making cabochons, jewelry inserts, and tumbled decorative stones. It is also a very common stone for beginning collectors.

Geological facts

Jasper is an opaque variety of chalcedony. When it is translucent, it is technically an agate, but many specimens like this one show a mix of opaque jasper and translucent quartz crystallization.

Field identification & locations

Identify in the field by its smooth, waxy feel when wet and its inability to be scratched by a steel knife. Commonly found in riverbeds, desert washes, and volcanic outcroppings in regions like the Western United States and Brazil.

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