mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness of 7 on the Mohs scale, variable color including clear, white, yellow, and brown due to impurities, vitreous to greasy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified August 3, 2026More mineral →

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Physical properties

Formation & geological history

Formed in a wide variety of geological environments, commonly crystallizing from silica-rich hydrothermal veins or as a primary component of igneous, metamorphic, and sedimentary rocks. This specific specimen has been weathered and water-worn into a rounded pebble shape in a river or beach environment.

Uses & applications

Used in glassmaking, abrasives, foundry sands, electronic oscillators, gemstone carvings, and as decorative landscape or aquarium gravel.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. Its high resistance to chemical and physical weathering allows quartz pebbles to persist in sedimentary cycles long after other minerals have broken down.

Field identification & locations

Easily identified by its high hardness (it will easily scratch glass and cannot be scratched by a steel knife) and its distinct conchoidal fracture. Found worldwide in riverbeds, beaches, and glacial deposits.