mineral

Quartz River Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent tan; Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent tan
Luster: Vitreous to waxy (when water-worn)

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or igneous crystallization from silica-rich magma; subsequently weathered and tumbled in high-energy aqueous environments like rivers or beaches over thousands of years.

Uses & applications

Used in decorative landscaping, as river rock for drainage, in glass manufacturing, and as an abrasive; sometimes used as a gem-quality material for tumbling or carving.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This specific specimen shows 'impact marks' or crescent-shaped bruises indicative of transport in high-energy water environments.

Field identification & locations

Identify by its ability to scratch glass and lack of reaction to acid. Commonly found in riverbeds, glacial tills, and shorelines worldwide. Collectors look for clarity and internal inclusions.