sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Hardness: 6.5-7 Mohs; Color: Brick red to deep brown-red; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
- Hardness
- 6
- Color
- Brick red to deep brown-red
- Luster
- Vitreous to dull
Identified More sedimentary →
Explore Red Jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 Mohs; Color: Brick red to deep brown-red; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
Formation & geological history
Formed via the deposition of silica from hydrothermal solutions or volcanic ash in sedimentary environments, where iron impurities provide the red pigmentation. It can occur in Precambrian to relatively modern geological formations.
Uses & applications
Used extensively for lapidary work, jewelry (cabochons, beads), decorative carvings, and as a popular collector's stone due to its ability to take a high polish.
Geological facts
Red Jasper has been used since antiquity as a 'stone of endurance' and was frequently used in Minoan Crete for seals. It is a variety of chalcedony that contains enough mineral impurities to make it opaque.
Field identification & locations
Identify by its deep red color, high hardness, and smooth, waxy feel when polished. It is commonly found in riverbeds, deserts, and volcanic regions worldwide, including South Africa, Brazil, and the USA.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary