mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Translucent white to milky; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Translucent white to milky
Luster: Vitreous to waxy

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Translucent white to milky; Luster: Vitreous to waxy; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed through the crystallization of magma or precipitation from hydrothermal veins. This specific specimen has been smoothed and rounded by water erosion in a fluvial (river) environment.

Uses & applications

Used in glassmaking, electronics, abrasives, and as decorative gravel or landscaping stone. Higher quality specimens are used for semi-precious jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically and physically very stable, which is why it often survives as pebbles long after other minerals have weathered away.

Field identification & locations

Identify by its hardness (scratches glass), waxy luster when tumbled, and lack of cleavage. Common in riverbeds and beaches worldwide. Collectors should look for unique inclusions or colors.