sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Hardness: 6.5-7 Mohs; Color: Brick red to deep dark red; Luster: Dull to vitreous; Structure: Microcrystalline (Cryptocrystalline) Quartz; Cleavage: None (Conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to deep dark red
Luster: Dull to vitreous

Identified July 7, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed via the deposition of silica from hydrothermal solutions or in sedimentary environments where iron oxides (hematite) provide the red pigment. It is often found in prehistoric iron-rich sedimentary deposits.

Uses & applications

Used extensively for lapidary work, jewelry (cabochons, beads), decorative carvings, and as a popular specimen for rock collectors. Historically used for making stone tools due to its hardness and fracture.

Geological facts

Red jasper has been used since antiquity; it was known as the 'rain bringer' in some cultures and was mentioned in the Bible. It is an opaque variety of chalcedony.

Field identification & locations

Identify by its deep red color and extreme hardness (it will scratch glass). Look for it in river beds or areas with iron-rich soil. It is commonly found in India, Russia, Brazil, and the USA.

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Sandstone or Siltstone

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Cone-in-cone structure (Limestone)

Cone-in-cone structure (Secondary Sedimentary Structure)

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Sandstone Grain

Clastic Sedimentary Rock Grain (SiO2 dominated)

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Chert Breccia

Brecciated Chert (Microcrystalline Silica)

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Shale or Slaty Mudstone

Argillaceous sedimentary rock

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Sandstone

Arenite (primarily SiO2)

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