mineral

Quartz (Water-worn Pebble)

Silicon Dioxide (SiO2)

Hardness 7 on the Mohs scale, yellowish-tan to translucent honey-orange color, vitreous to waxy luster, conchoidal fracture, trigonal crystal system in origin, specific gravity approx 2.65.

Identified July 27, 2026More mineral →

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Physical properties

Hardness 7 on the Mohs scale, yellowish-tan to translucent honey-orange color, vitreous to waxy luster, conchoidal fracture, trigonal crystal system in origin, specific gravity approx 2.65.

Formation & geological history

Formed from silica-rich hydrothermal solutions or cooling magma. This particular rounded specimen was weathered and naturally smoothed by water action in a river, stream, or beach environment.

Uses & applications

Used widely in decorative rock collections, lapidary arts, tumbling, jewelry, and industrially for glassmaking and electronics grade silica.

Geological facts

Quartz is one of the most abundant minerals on Earth's continental crust. Rounded quartzite and quartz pebbles like this are often referred to as river agate, carnelian-toned quartz, or 'floater' stones.

Field identification & locations

Identify in the field by its hardness (scratches glass, cannot be scratched by a steel knife), lack of cleavage, smooth waxy surface when river-worn, and high light translucency. Commonly found along gravel bars, riverbeds, and ocean beaches worldwide.