sedimentary

Jasper (Red/Brown)

Silicon Dioxide (SiO2) with iron oxide inclusions

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown to tan; Luster: Dull to waxy; Crystal Structure: Microcrystalline (trigonal); Cleavage: None/Conchoidal fracture.

Hardness: 6
Color: Reddish-brown to tan
Luster: Dull to waxy

Identified March 21, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown to tan; Luster: Dull to waxy; Crystal Structure: Microcrystalline (trigonal); Cleavage: None/Conchoidal fracture.

Formation & geological history

Formed from silica-rich fluids (often volcanic or hydrothermal in origin) that saturate sediment or volcanic ash, slowly precipitating microcrystalline quartz over millions of years.

Uses & applications

Commonly used for decorative lapidary work, cabochons for jewelry, small carvings, and as a component in aquarium gravel or landscaping.

Geological facts

Jasper is an opaque variety of chalcedony. Its name comes from the Greek word 'iaspis', meaning 'spotted stone.' It has been used by ancient civilizations for amulets and cylinder seals for thousands of years.

Field identification & locations

Identify in the field by its smooth, water-worn texture when found in riverbeds, its high hardness (it will scratch glass), and its completely opaque nature. Found globally, especially in Oregon, Idaho, and Western Australia.