Sedimentary

Jasper

Silicon dioxide / Chalcedony (SiO2)

Hardness: 6.5-7 (Mohs scale); Color: Red and brownish-green; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Hardness: 6
Color: Red and brownish-green
Luster: Dull to waxy

Identified April 24, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs scale); Color: Red and brownish-green; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica in mineral springs or hydrothermal veins. This sample appears to be a water-worn river stone, likely dating back millions of years. The red color is caused by iron (hematite) inclusions.

Uses & applications

Commonly used for lapidary work, jewelry (cabochons), river rock landscaping, and as a collectible gemstone for metaphysical or aesthetic purposes.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'jasper' comes from the Greek word 'iaspis', meaning spotted stone. It has been used for centuries to carve seals and amulets in ancient civilizations.

Field identification & locations

Look for a smooth, matte finish that doesn't let light pass through even at the edges (opaque). Frequently found in riverbeds and beaches where the silica content prevents quick erosion. It will scratch steel but not glass.