sedimentary

Red Jasper (Chert)

Silicon Dioxide (SiO2) with iron oxide inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 (Mohs scale), Color: Red, brown, and yellowish-tan, Luster: Dull to waxy, Crystal structure: Microcrystalline/Cryptocrystalline, Cleavage: None (conchoidal fracture)

Hardness: 6

Identified June 18, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale), Color: Red, brown, and yellowish-tan, Luster: Dull to waxy, Crystal structure: Microcrystalline/Cryptocrystalline, Cleavage: None (conchoidal fracture)

Formation & geological history

Formed from the deposition of silica-rich fluids in cracks or as nodules within sedimentary or volcanic rocks. The red color is caused by the oxidation of iron (hematite) during formation.

Uses & applications

Commonly used for lapidary work, jewelry (cabochons), interior decoration, and as a healing stone in metaphysical practices.

Geological facts

The name jasper is derived from the Greek 'iaspis', meaning spotted stone. It has been used since antiquity for royal seals and amulets.

Field identification & locations

Identify by its opacity (even on thin edges), smooth conchoidal fracture, and inability to be scratched by a steel knife. Frequently found in riverbeds and coastal regions as water-worn pebbles.