sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Whitish to translucent light brown; Luster: Vitreous to greasy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Whitish to translucent light brown
Luster: Vitreous to greasy

Identified August 5, 2026More sedimentary →

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Physical properties

Hardness: 7 on Mohs scale; Color: Whitish to translucent light brown; Luster: Vitreous to greasy; Crystal structure: Trigonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from the weathering and erosion of parent igneous or metamorphic rocks, subsequently rounded and smoothed through water transport in marine, river, or beach environments.

Uses & applications

Used in landscaping, decorative gravel, aggregate in construction, and by hobbyist lapidaries for tumbling and polishing.

Geological facts

Quartz is one of the most abundant minerals in the Earth's continental crust and is exceptionally resistant to both mechanical and chemical weathering, which is why it often survives as durable pebbles on beaches.

Field identification & locations

Found worldwide along riverbeds, beaches, and glacial outwash. Identified by its high hardness (scratches glass), lack of cleavage, and smooth, water-worn shape.