sedimentary

Jasper (Iron-rich)

Silicon Dioxide (SiO2) with Fe2O3 (Hematite) inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale. Color: Opaque brown, reddish-brown, and tan. Luster: Dull to waxy. Structure: Microcrystalline/Cryptocrystalline. Specific Gravity: 2.58-2.91.

Hardness: 6
Color: Opaque brown, reddish-brown, and tan
Luster: Dull to waxy

Identified February 28, 2026More sedimentary →

Explore Jasper (Iron-rich) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 6.5-7 on Mohs scale. Color: Opaque brown, reddish-brown, and tan. Luster: Dull to waxy. Structure: Microcrystalline/Cryptocrystalline. Specific Gravity: 2.58-2.91.

Formation & geological history

Formed from the deposition of silica-rich fluids in cracks or volcanic cavities, often associated with hydrothermal activity. Over time, the silica crystallizes into microcrystalline quartz, with high iron content providing the brown/red pigmentation.

Uses & applications

Commonly used in lapidary work for making cabochons, beads, and decorative carvings. Historically used for making stone tools and seal stones.

Geological facts

Jasper is an opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning spotted stone. It is often found as smooth water-worn pebbles in riverbeds due to its extreme durability and resistance to weathering.

Field identification & locations

Look for a smooth, waxy texture when wet and a conchoidal (shell-like) fracture pattern. It is much harder than steel and cannot be scratched by a knife. Commonly found in riverbeds, deserts, and coastal areas globally.