sedimentary
Chert (Yellow Jasper)
Cryptocrystalline Quartz (SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Mustard yellow to brownish-yellow; Luster: Waxy to vitreous; Structure: Microcrystalline; Cleavage: None (conchoidal fracture).
- Hardness
- 6
- Color
- Mustard yellow to brownish-yellow
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Mustard yellow to brownish-yellow; Luster: Waxy to vitreous; Structure: Microcrystalline; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed from the accumulation of silica-rich microfossils (like radiolarians) or chemical precipitation from groundwater. This specimen appears water-worn or weathered, likely originating from sedimentary beds.
Uses & applications
Historically used for stone tools (lithics) due to its sharp edges when fractured. Modernly used for lapidary work, jewelry, and as landscaping stone.
Geological facts
Yellow jasper is often associated with the solar plexus chakra in metaphysical circles. This specific piece shows signs of percussion flaking, suggesting it might be an anthropogenic lithic flake or tool.
Field identification & locations
Identify by its waxy appearance, smooth conchoidal (shell-like) fractures, and inability to be scratched by a steel nail. Commonly found in riverbeds or limestone deposits globally.
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