sedimentary
Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide inclusions)
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs scale); Color: Brown, opaque; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91
- Hardness
- 6
- Color
- Brown, opaque
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Brown, opaque; Luster: Dull to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91
Formation & geological history
Formed through the infiltration of silica-rich fluids into volcanic ash or fine-grained sediments, often associated with hydrothermal activity. This specimen shows significant wind or water erosion smoothing.
Uses & applications
Commonly used in lapidary arts for cabochons, beads, and pocket stones. Historically used for making tools and seals.
Geological facts
The brown color is typically caused by high iron oxide (goethite or limonite) content. Jasper has been used by humans for ornament and utility since the Neolithic period.
Field identification & locations
Look for a smooth, opaque, waxy texture and hardness that can scratch glass. This water-worn pebble shape is typical for jasper found in riverbeds or coastal environments.
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