sedimentary

Red Jasper

Silicon Dioxide (SiO2)

Hardness: 6.5-7 Mohs; Color: Brick red to deep brownish-red; Luster: Dull to sub-vitreous; Crystal Structure: Microcrystalline; Specific Gravity: 2.58-2.91

Hardness: 6
Color: Brick red to deep brownish-red
Luster: Dull to sub-vitreous

Identified July 2, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 Mohs; Color: Brick red to deep brownish-red; Luster: Dull to sub-vitreous; Crystal Structure: Microcrystalline; Specific Gravity: 2.58-2.91

Formation & geological history

Formed when fine-grained silica-rich sediments or volcanic ash become saturated with iron-rich fluids during lithification. The oxygenation of iron minerals produces the characteristic red color. Often found as nodules or in veins.

Uses & applications

Used for lapidary work, jewelry (beads, cabochons), carvings, and as a popular specimen for collectors.

Geological facts

Red Jasper is known for its intense color caused by up to 20% iron oxide (hematite) inclusions. It has been used since antiquity in seals, jewelry, and talismans across Egyptian and Greek civilizations.

Field identification & locations

Identify in the field by its opaque red color, smooth waxy feel when wet, and conchoidal fracture. Common in gravel beds, riverside deposits, and coastal areas. It will not scratch with a steel knife but can scratch glass.