mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

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

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

Identified June 10, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. This specific specimen is a 'clast' that has been rounded by fluvial (river) or marine erosion over thousands of years.

Uses & applications

Small pebbles are used as decorative garden mulch, in aquarium substrates, or naturally as part of gravel for construction and road bases. High-purity quartz is used in electronics and glassmaking.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Because of its high hardness and chemical stability, it survives weathering much longer than other minerals, which is why most beach sand is composed of quartz.

Field identification & locations

Identify in the field by its hardness (it should scratch glass) and lack of cleavage. Look for the 'frosted' or waxy surface common in river-tumbled stones. They are ubiquitous in riverbeds and glacial tills worldwide.