sedimentary

Red Jasper (with Chert/Quartz)

Silicon Dioxide (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish-orange; Luster: Dull to Vitreous; Crystal Structure: Microcrystalline/Cryptocrystalline; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to brownish-orange
Luster: Dull to Vitreous

Identified July 5, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when silica-rich fluids permeate sedimentary or volcanic rocks. The red color is caused by the inclusion of iron oxides (hematite) during the crystallization process. Found in hydrothermal veins and as nodules in sedimentary layers.

Uses & applications

Used extensively as a gemstone, for decorative carvings, lapidary work, and historically as an architectural stone. It is also a popular collector's specimen.

Geological facts

Red jasper has been used since antiquity; it was known as the 'stone of endurance' in many cultures. It is a variety of chalcedony that contains up to 20% foreign materials which account for its color and opacity.

Field identification & locations

Identify in the field by its waxy to dull luster, smooth conchoidal (shell-like) fractures, and its ability to scratch glass. Commonly found in riverbeds or desert regions of India, Brazil, and the Southwestern United States.

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Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Cone-in-cone structure (Limestone)

Cone-in-cone structure (Secondary Sedimentary Structure)

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Chert Breccia

Brecciated Chert (Microcrystalline Silica)

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Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

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Shale or Slaty Mudstone

Argillaceous sedimentary rock

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Sandstone

Arenite (primarily SiO2)

sedimentary