sedimentary

Red Jasper

Silicon Dioxide (SiO2) with Iron Oxide inclusions

Hardness: 6.5-7 on Mohs scale; Color: Dark red to reddish-brown; Luster: Vitreous to dull (smooth polished finish); Crystal structure: Microcrystalline/Cryptocrystalline trigonal; Cleavage: None, conchoidal fracture; Specific gravity: 2.58-2.91.

Hardness: 6
Color: Dark red to reddish-brown
Luster: Vitreous to dull (smooth polished finish)

Identified July 24, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed as silica-rich fluids permeate micro-porous rocks or volcanic ash, absorbing iron oxide minerals (hematite) which give it its characteristic deep red hue.

Uses & applications

Commonly used for tumbled stones, cabochons, lapidary art, beads, ornamental carvings, and gemstone collections.

Geological facts

Red Jasper has been used since antiquity in seals, amulets, and decorative arts. It is known for its opaque, rich color caused by iron impurities embedded within the quartz matrix.

Field identification & locations

Identify by its opaque reddish-brown appearance, smooth tumbled texture, and high hardness (cannot be scratched by a steel knife). Commonly found in alluvial gravels, basalt flows, and sedimentary deposits worldwide (e.g., South Africa, Brazil, India, USA).

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