sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, color ranges from white to off-white or yellowish due to weathering, vitreous to dull luster, trigonal crystal system when formed as crystals but amorphous/rounded here due to transport, conchoidal fracture, specific gravity of 2.65.

Identified August 4, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from preexisting rocks through weathering and erosion, where quartz is exceptionally resistant to chemical and physical breakdown. Over long periods, river or wave action rounds the fragments into smooth pebbles.

Uses & applications

Used in landscaping, decorative gravel, aggregate in construction, and as a raw material for silicon and glass production.

Geological facts

Quartz is one of the most abundant and durable minerals in the Earth's continental crust. Its high resistance to weathering is why quartz pebbles are ubiquitous in riverbeds and beaches worldwide.

Field identification & locations

Identified by its high hardness (scratches glass), lack of reaction to acid, and smooth, water-worn shape. Commonly found in stream beds, beaches, and conglomeratic sedimentary rock formations.