mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: tan to creamy white with orange iron staining, Luster: Vitreous to waxy (when tumbled), Crystal Structure: Trigonal/Hexagonal, Specific Gravity: 2.65

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: tan to creamy white with orange iron staining, Luster: Vitreous to waxy (when tumbled), Crystal Structure: Trigonal/Hexagonal, Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen has been smoothed and rounded by the mechanical action of water (river or stream) over geological time.

Uses & applications

Common quartz pebbles are used in landscaping, as aggregate in construction, or for lapidary tumbling. High-purity quartz is used in electronics and glass manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. River pebbles like this one often survive long after other minerals have weathered away due to their high chemical and physical resistance.

Field identification & locations

Identify by its hardness (cannot be scratched by a steel nail) and lack of cleavage (it breaks with a conchoidal, shell-like fracture). It is found globally in riverbeds, beaches, and soil deposits.