mineral

Chalcedony (Agate / Jasper Pebble)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 6.5-7 on Mohs scale. Color: Translucent yellowish-brown to dark amber with internal inclusions. Luster: Waxy to vitreous. Crystal Structure: Microcrystalline aggregate (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.58-2.64.

Hardness: 6
Luster: Waxy to vitreous

Identified July 27, 2026More mineral →

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Physical properties

Formation & geological history

Formed via low-temperature deposition of silica from water solutions in cavities, fractures, or sedimentary environments. Naturally rounded and polished by stream or wave action.

Uses & applications

Used in lapidary arts, jewelry making, tumbled stone collections, decorative crafts, and metaphysical practices.

Geological facts

Chalcedony is a cryptocrystalline form of silica composed of very fine intergrowths of quartz and moganite. Water-worn beach or river pebbles like this often exhibit natural translucency when backlit.

Field identification & locations

Identified by its waxy luster, hardness (scratches glass), translucency, smooth water-worn surface, and lack of distinct cleavage. Commonly found along riverbeds, lakeshores, and ocean beaches worldwide.