mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness of 7 on the Mohs scale. Color ranges from clear/white to yellow, amber, or brown due to iron staining. Luster is vitreous (glassy) to greasy. Crystal system is trigonal. Conchoidal fracture with no true cleavage. Specific gravity is approximately 2.65.

Identified July 31, 2026More mineral →

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Physical properties

Formation & geological history

Quartz is one of the most abundant minerals in the Earth's crust. This pebble was likely formed through the weathering and erosion of parent igneous or metamorphic rocks, followed by extensive water transport in a river, stream, or beach environment, which smoothed and rounded its edges.

Uses & applications

Commonly collected by hobbyists and children. High-purity quartz is used extensively in industry for glassmaking, electronics, optics, and silicon wafers.

Geological facts

Quartz is remarkably resistant to both mechanical weathering and chemical weathering, which is why quartz pebbles are extremely common in stream beds and gravel bars all over the world.

Field identification & locations

Can be identified easily in the field by its high hardness (it will easily scratch glass) and lack of cleavage. Found worldwide in riverbeds, beaches, and glacial deposits.