sedimentary

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 Mohs; Color: Brick red to brownish red; Luster: Dull to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to brownish red
Luster: Dull to vitreous

Identified June 8, 2026More sedimentary →

Explore Red Jasper in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 6.5-7 Mohs; Color: Brick red to brownish red; Luster: Dull to vitreous; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica-rich sediments in deep sea environments or through the infiltration of silica-rich fluids in volcanic ash or other porous rocks. The red color is derived from high hematite (iron oxide) inclusions.

Uses & applications

Commonly used for lapidary work, cabochons, beads for jewelry, ornamental carvings, and as a decorative stone in landscaping. Historically used for weapons and tools due to its conchoidal fracture.

Geological facts

Red Jasper has been used by many ancient civilizations; the Ancient Egyptians associated it with the blood of Isis. It is a variety of chalcedony that is opaque due to its high mineral impurity content.

Field identification & locations

Identify in the field by its deep red color, extreme hardness (it will scratch glass), and smooth, shell-like fracture surfaces. Frequently found in stream beds or as rounded pebbles on beaches in volcanic regions.