mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to light tan with iron staining; Luster: Vitreous to waxy when wet; Crystal structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to light tan with iron staining
Luster: Vitreous to waxy when wet

Identified June 19, 2026More mineral →

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Physical properties

Formation & geological history

Formation process involves silica-rich fluids precipitating in rock cavities or veins. This specific specimen is a water-worn river pebble, shaped and smoothed by fluvial erosion over thousands of years.

Uses & applications

Used in landscaping, glass manufacturing, abrasives, and as decorative river stones. High-purity quartz is also used in electronics and watches.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded pebbles are often referred to as 'river rocks' and are found globally in active and ancient stream beds.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and smooth, rounded surface from water transport. Commonly found in riverbeds, beaches, and glacial deposits.