sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Hematite impurities

Hardness: 6.5-7 (Mohs scale); Color: Brick red to deep terracotta; Luster: Vitreous to dull/waxy when polished; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Brick red to deep terracotta
Luster: Vitreous to dull/waxy when polished

Identified March 25, 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 through the deposition of silica from mineral springs or hydrothermal vents into volcanic or sedimentary rocks. The red coloring comes from high iron/hematite content. It can be found in formations ranging from Precambrian to recent ages.

Uses & applications

Mostly used for semi-precious jewelry (beads, cabochons), ornamental carvings, stone inlays, and as a popular stone for gemstone collecting and lapidary practice.

Geological facts

Jasper has been used as a gemstone since antiquity; it was known as the 'rain bringer' in some Native American cultures and was featured in the breastplate of the High Priest in Biblical descriptions.

Field identification & locations

Identify in the field by its opaque nature (unlike Carnelian which is translucent), its smooth waxy surface when damp, and its extreme hardness (will scratch glass). Commonly found in riverbeds and coastal regions of South Africa, Brazil, and the Southwestern USA.

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