sedimentary

Jasper

Silicon Dioxide (SiO2), microcrystalline quartz

Hardness of 6.5 to 7 on the Mohs scale, predominantly reddish-brown to brick-red color due to iron oxide impurities, waxy to dull luster, cryptocrystalline crystal structure, conchoidal fracture with no cleavage, specific gravity around 2.58 to 2.91.

Identified August 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms by the precipitation of silica-rich fluids in sedimentary environments, often involving volcanic ash or silica-rich hydrothermal solutions filling rock cavities. Geological age varies widely depending on the specific deposit, frequently associated with Precambrian banded iron formations.

Uses & applications

Used widely in ornamental carvings, jewelry, cabochons, polished stones, and decorative objects.

Geological facts

Jasper has been used since ancient times for talismans, seals, and weaponry components like arrowheads. Its name derives from the ancient Greek word for 'spotted stone'.

Field identification & locations

Can be identified in the field by its opaque nature, hardness (scratches glass), waxy luster, and lack of visible crystal grains. Commonly found in riverbeds, glacial drift, and areas with ancient volcanic or sedimentary activity worldwide.

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Fossiliferous Concretion

Septarian Concretion containing Brachiopods/Crinoids

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Generic Pebble / Rock Fragment

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Banded Siltstone / Mudstone Pebble

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Sedimentary Sandstone

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