mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky to translucent white/tan; Luster: Vitreous (glassy) to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky to translucent white/tan
Luster: Vitreous (glassy) to greasy

Identified April 1, 2026More mineral →

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Physical properties

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous pegmatites. This specific specimen appears water-worn, indicating it was eroded from its source rock and tumbled in a river, stream, or beach environment over thousands of years.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, and as decorative landscaping gravel. Translucent varieties are often used in lapidary work for tumbled stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is highly resistant to chemical and physical weathering, which is why it often remains as smooth pebbles long after other minerals in a rock have decomposed.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife and its lack of cleavage planes. It often appears as rounded, frosted white or glassy translucent stones in gravel pits or riverbeds.