sedimentary

Quartz Pebble

Silicon dioxide (SiO2)

Hardness of 7 on the Mohs scale; color is yellowish-orange due to iron oxide staining; vitreous to greasy luster; crystal system is trigonal (microcrystalline or massive in tumbled form); conchoidal fracture with no true cleavage; specific gravity around 2.65.

Identified August 2, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the weathering and erosion of parent rocks containing quartz veins or pegmatites, followed by water transport in rivers or streams which smoothed and rounded the edges over long periods of geological time.

Uses & applications

Commonly used in landscaping, decorative gravel, tumbled stones, spiritual/metaphysical practices, and occasionally in glassmaking or abrasive manufacturing.

Geological facts

Quartz is one of the most abundant minerals on Earth's continental crust. Its high resistance to chemical weathering allows quartz pebbles to survive long journeys in riverbeds and beaches long after less durable minerals have worn away.

Field identification & locations

Easily identified in the field by its high hardness (it can scratch glass), lack of cleavage, and smooth water-worn shape. Found globally in riverbeds, lake shores, and gravel deposits.