mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Yellowish-tan to milky white; Luster: Vitreous to waxy (when water-worn); Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Yellowish-tan to milky white
Luster: Vitreous to waxy (when water-worn)

Identified July 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed primarily in igneous and metamorphic rocks, these specific specimens are water-worn tumbled pebbles found in riverbeds or coastal environments, where they have been smoothed by erosion over thousands of years.

Uses & applications

Used in decorative landscaping, aquarium gravel, as a source for silicon in glass making, and as a durable material for construction aggregates. Small smooth pebbles are also used for gemstone tumbling or as 'worry stones'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These specific rounded shapes are called 'clasts' and indicate a high-energy transport environment, such as a fast-flowing stream or beach.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and smooth, rounded exterior. Often found in gravel pits, beaches, and creek beds worldwide.