
mineral
Jasper (Chert / Chalcedony)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
AI-generated identification · may be incorrectHardness: 6.5-7 on the Mohs scale. Luster: Waxy to vitreous. Color: Reddish-brown, tan, and yellowish tones. Cleavage: None (conchoidal fracture). Microcrystalline aggregate structure.
- Hardness
- 6
- Color
- Reddish-brown, tan, and yellowish tones
- Luster
- Waxy to vitreous
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Physical properties
Hardness: 6.5-7 on the Mohs scale. Luster: Waxy to vitreous. Color: Reddish-brown, tan, and yellowish tones. Cleavage: None (conchoidal fracture). Microcrystalline aggregate structure.
Formation & geological history
Formed through the deposition of silica-rich fluid filling cavities, veins, or sedimentary layers, often associated with volcanic activity or deep-sea sedimentary deposits.
Uses & applications
Used widely for lapidary work, decorative carvings, tumbling, cabochons for jewelry, and as a popular rockhounding collectible.
Geological facts
Red and brown colorations in jasper are caused by the presence of iron oxide minerals like hematite and goethite within the microcrystalline quartz matrix.
Field identification & locations
Field identification features a smooth, waxy surface, shell-like (conchoidal) fracturing, and opacity. Commonly found in stream beds, volcanic gravels, and agate-bearing regions worldwide.