mineral

Jasper (Chert / Chalcedony)

Silicon Dioxide (SiO2) with Iron Oxide inclusions

AI-generated identification · may be incorrect

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.

Hardness: 6
Color: Reddish-brown, tan, and yellowish tones
Luster: Waxy to vitreous

Identified July 21, 2026More mineral →

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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.