sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish-red with dark streaks; Luster: Dull to waxy when unpolished; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to brownish-red with dark streaks
Luster: Dull to waxy when unpolished

Identified June 14, 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 via the deposition of silica from water-saturated environments or hydrothermal circulation, usually within volcanic or sedimentary settings. The red color is caused by the inclusion of iron oxide (hematite) during formation.

Uses & applications

Commonly used as a gemstone for jewelry, decorative carvings, beads, and stone therapy. It is also a popular specimen for lapidary work due to its ability to take a high polish.

Geological facts

Known as the 'Stone of Endurance' in folklore, jasper has been used for seals and amulets since ancient Mesopotamian times. It is a variety of chalcedony that contains up to 20% foreign materials which determine its color and opacity.

Field identification & locations

Identify in the field by its opaque nature (unlike translucent carnelian), smooth texture, and inability to be scratched by a steel knife. Frequently found in riverbeds or coastal areas as water-worn pebbles.

Other sedimentary specimens

See all

Sandstone or Siltstone

Arenite (if sandstone)

Sedimentary

Sandstone

Arenite (primarily SiO2)

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

sedimentary