mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale. Color: Translucent tan to brownish-orange. Luster: Vitreous to waxy when water-worn. Crystal Structure: Hexagonal (trigonal). Cleavage: None (conchoidal fracture). Specific Gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Translucent tan to brownish-orange
Luster: Vitreous to waxy when water-worn

Identified April 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen has been Rounded and smoothed through fluvial erosion (river action), likely over thousands of years.

Uses & applications

Common river stones are used for landscaping, aquarium decor, and as decorative gravel. Higher quality quartz is used in jewelry and electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which had its origins in Slavic and West Slavic languages.

Field identification & locations

Identify in the field by its hardness (it can scratch glass), its translucent appearance, and its lack of cleavage. Commonly found in riverbeds, beaches, and gravel pits worldwide.