mineral

Quartz Pebble

Silicon Dioxide (SiO2)

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

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

Identified April 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous (glassy) to waxy; 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 specimen appears water-worn, indicating it was shaped by fluvial (river) or coastal erosion processes.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative landscape stone or river rock in construction.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz gets its cloudy appearance from tiny fluid inclusions of gas or liquid trapped during crystal growth.

Field identification & locations

Identify in the field by its hardness (cannot be scratched by a steel knife) and lack of cleavage. Common in riverbeds, beaches, and soil worldwide as it is highly resistant to weathering.