mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent grey; Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal (though not visible in tumbled pebble form); Cleavage: None/Conchoidal fracture.

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

Identified May 9, 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 by mechanical weathering and transport in water over hundreds to thousands of years.

Uses & applications

Used in construction aggregates, glass making, laboratory equipment, and as decorative landscape gravel. Smooth pebbles are often used in aquariums or for massage therapy.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its resistance to physical and chemical weathering allows it to survive long transport distances in rivers, resulting in these rounded pebbles.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and pocket knife blades) and lack of cleavage. It is extremely common in riverbeds, beaches, and glacial deposits worldwide.