mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: cloudy white/translucent grey, Luster: vitreous to waxy (when water-worn), Crystal structure: Trigonal (often appears amorphous in pebbles), Cleavage: none, Specific Gravity: 2.65

Identified June 1, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms in many environments including igneous, metamorphic, and sedimentary rocks. These specific rounded pebbles are formed through the erosion of larger quartz veins, followed by mechanical weathering and transport in riverbeds or coastal environments.

Uses & applications

Common quartz is used in the manufacture of glass, ceramics, and as an abrasive in sandblasting. In pebble form, it is widely used in landscaping and as a gravel component.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded pebbles are often referred to as 'river stones' and have been smoothed over hundreds or thousands of years of water transport.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage (it breaks with a conchoidal/shell-like fracture). It is commonly found in riverbeds, beaches, and glacial deposits worldwide.