sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: White, gray, yellowish brown due to weathering. Luster: Vitreous to dull. Crystal structure: Trigonal. Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: White, gray, yellowish brown due to weathering
Luster: Vitreous to dull

Identified July 31, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the mechanical weathering and erosion of quartz-bearing parent rocks such as granite or quartzite, followed by water transport and rounding in riverbeds or marine environments.

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 Earth's continental crust, making it extremely resistant to chemical weathering, which is why it often survives as rounded pebbles in streams and beaches.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass), lack of cleavage, and resistance to acid. Commonly found in riverbeds, glacial tills, and sedimentary conglomerates worldwide.