sedimentary

Quartz Pebble

Silicon dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White, grayish, or translucent. Luster: Vitreous to dull due to weathering. Crystal structure: Trigonal (microcrystalline or massive in pebbles). Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: White, grayish, or translucent
Luster: Vitreous to dull due to weathering

Identified July 31, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the mechanical weathering and water transport of larger quartz veins or igneous/metamorphic rocks, resulting in a smooth, rounded pebble found in stream beds, beaches, or alluvial deposits.

Uses & applications

Used in landscaping, decorative gravel, tumbling, and occasionally in glassmaking or abrasive manufacturing.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust. Its high resistance to chemical weathering allows quartz pebbles to survive long journeys in river systems where softer minerals are worn away.

Field identification & locations

Easily identified by its hardness (scratches glass), lack of cleavage, and smooth water-worn shape. Commonly found in river gravels and sedimentary formations worldwide, including the North Carolina Piedmont region.