Jasper (with Agate/Chalcedony inclusions)

Silicon Dioxide (SiO2)

Rock Type: sedimentary

Jasper (with Agate/Chalcedony inclusions)

Physical Properties

Hardness: 6.5-7 (Mohs scale), Color: Red, white, and translucent grey swirls, Luster: Waxy to vitreous when wet or polished, Crystal Structure: Microcrystalline (trigonal), Cleavage: None (conchoidal fracture)

Formation & Geological History

Formed through the deposition of silica from volcanic ash or hydrothermal solutions into cavities or fissures. This specimen likely tumbled in a river or stream, resulting in its smooth, rounded shape.

Uses & Applications

Used primarily for lapidary work, jewelry (cabochons and beads), ornamental stones, and as a popular specimen for rock tumbling and collecting.

Geological Facts

Jasper is an opaque variety of chalcedony; when it has translucent areas like the grey/white sections seen here, it is often transitioning into agate. These stones have been used since antiquity for seals and amulets.

Field Identification & Locations

Identify in the field by its hardness (cannot be scratched by a steel knife), smooth 'river-worn' texture, and colorful swirls. Commonly found in riverbeds and gravel pits in volcanic regions.

Identified on: 4/19/2026

Mode: Standard