Red Jasper

Silicon dioxide (SiO2) with iron inclusions

Rock Type: sedimentary

Red Jasper

Physical Properties

Hardness: 6.5-7 (Mohs scale); Color: Brick red to brownish red due to iron(III) oxide; Luster: Vitreous to dull; Crystal system: Trigonal/Microcrystalline; Cleavage: None; Fracture: Conchoidal.

Formation & Geological History

Forms from the accumulation of microcrystalline quartz or chalcedony in hydrothermal veins or sedimentary deposits, often enriched with high iron oxide content which provides the red coloration.

Uses & Applications

Primarily used for decorative purposes, lapidary art, jewelry (cabochons and beads), and as a collector's gemstone. Historically used as a material for seals and tools.

Geological Facts

Jasper was a favorite gem in the ancient world, mentioned in biblical texts and used consistently across Greek, Roman, and Mesopotamian cultures for protective amulets.

Field Identification & Locations

Identify by its solid red color, inability to be scratched by a steel blade, and smooth, curved (conchoidal) fracture lines. Commonly found in riverbeds, glacial deposits, and gravel pits globally.

Identified on: 5/17/2026

Mode: Standard