mineral

Quartz Geode Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, translucent, with a reddish-orange iron inclusion; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, translucent, with a reddish-orange iron inclusion
Luster: Vitreous to waxy

Identified May 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the precipitation of silica from groundwater within cavities (vesicles) of volcanic or sedimentary rocks. Over millions of years, these cavities are filled with quartz. This specific specimen has been water-worn into a smooth pebble shape.

Uses & applications

Used primarily by collectors and in lapidary work. Highly pure quartz is used in electronics and glass manufacturing, though small pebbles like this are mainly decorative or educational.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specimen shows a 'vug' or a small open cavity where individual crystals can be seen, classifying it as a micro-geode.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its waxy, translucent appearance when wet. Often found in riverbeds, beaches, or areas with eroded volcanic bedrock.