sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Hardness: 6.5-7 Mohs; Color: Brick red to deep brownish 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 brownish red
Luster: Vitreous to dull

Identified February 5, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed from the hydrothermal precipitation of silica in sedimentary environments or volcanic ash, often associated with iron-rich mineral deposition. It belongs to the chalcedony family and can date back millions of years.

Uses & applications

Extensively used for ornamental objects, cabochons for jewelry, therapy stones, and tumbled decorative stones. Historically used for seals and amulets.

Geological facts

Red Jasper is known as the 'stone of endurance' in ancient lore. Its deep red color comes from high concentrations of iron. It was a favorite gemstone in the ancient world, referenced in Greek, Roman, and Egyptian history.

Field identification & locations

Identified by its opaque red color, smoothness when polished, and inability to be scratched by a steel pocketknife. Common locations include Brazil, India, USA (Southwest), and South Africa. For collectors, look for solid saturated colors or interesting banding.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Sandstone

Arenite (primarily SiO2)

sedimentary

Shale or Slaty Mudstone

Argillaceous sedimentary rock

sedimentary

Chert Breccia

Brecciated Chert (Microcrystalline Silica)

sedimentary

Sandstone (Quartz-rich)

Arenite (SiO2)

sedimentary

Sandstone (with man-made markings)

Arenite (composed primarily of Quartz, SiO2)

sedimentary