sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2)

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

Hardness: 6
Color: Brick red to brownish red due to iron inclusions
Luster: Dull to vitreous

Identified February 15, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica from water (hydrothermal or sedimentary) that infills cracks and voids. The red color results from high concentrations of iron oxide (hematite) during its formation process, occurring in various geological ages globally.

Uses & applications

Used primarily for lapidary work, jewelry (cabochons and beads), decorative ornaments, and metaphysical collection. Historically used for seals and tools due to its hardness and lack of cleavage.

Geological facts

Ancient Egyptians used red jasper in amulets to represent the 'blood of Isis.' It is considered an 'opaque' variety of chalcedony that can contain up to 20% foreign materials, which determines its color and pattern.

Field identification & locations

Identify in the field by its opacity (unlike translucent carnelian), its red streak when rubbed on unglazed porcelain, and its smooth, shell-like fracture surfaces. Frequently found in riverbeds or desert regions as water-worn pebbles.