mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: milky white to translucent; Luster: vitreous to greasy; Crystal Structure: trigonal/hexagonal; Cleavage: none, conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: milky white to translucent
Luster: vitreous to greasy

Identified July 24, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: milky white to translucent; Luster: vitreous to greasy; Crystal Structure: trigonal/hexagonal; Cleavage: none, conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich magma or precipitation from hydrothermal fluids, then weathered, eroded, and rounded by water transport over long periods.

Uses & applications

Used in glassmaking, electronics, abrasives, construction aggregates, and widely collected as tumbled stones or landscaping gravel.

Geological facts

Quartz is the second most abundant mineral in the Earth's continental crust. Rounded stream pebbles like this one have been naturally tumbled by river or beach action over hundreds or thousands of years.

Field identification & locations

Identify in the field by its hardness (scratches glass easily), lack of cleavage, and translucent to milky appearance. Extremely common in stream beds, gravel pits, beaches, and soil worldwide.