mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Translucent white to light gray with slight tan staining, Luster: Vitreous to waxy, Crystal structure: Hexagonal (trigonal), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified June 8, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed from hydrothermal veins or as a primary constituent of igneous rocks like granite. This specific specimen has been weathered and rounded through transport in water (fluvial or beach environment) during the Quaternary period.

Uses & applications

Commonly used as high-grade silica for glass manufacturing, as an abrasive, in construction aggregate, and as a raw material for electronic microchips (silicon).

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is piezoelectric, meaning it generates an electric charge when mechanical pressure is applied, making it essential for clocks and radios.

Field identification & locations

Identify by its hardness (it will scratch glass), lack of cleavage, and rounded 'river rock' texture. It is ubiquitous in riverbeds and on beaches worldwide. Collectors often look for higher clarity or 'milky' varieties.