sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Red (due to iron inclusions); Luster: Vitreous to dull; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Red (due to iron inclusions)
Luster: Vitreous to dull

Identified April 18, 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 infiltration of silica-rich fluids into volcanic ash or fine-grained sediments. It often forms in hydrothermal environments or through the replacement of organic materials.

Uses & applications

Used primarily for ornamental purposes, jewelry (cabochons), lapidary art, and metaphysical practices. Historically used for tools and arrowheads due to its hardness.

Geological facts

Ancient Egyptians often wore red jasper amulets for protection. It is a variety of chalcedony and gets its deep red color primarily from hematite (iron oxide) impurities trapped within the silica.

Field identification & locations

Identify in the field by its waxy to dull luster, extreme hardness (it will scratch glass), and opaque nature even at thin edges. Look for smooth, shell-like (conchoidal) fractures on broken surfaces.