mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Milky white to translucent yellowish-tan; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on the Mohs scale
Color: Milky white to translucent yellowish-tan
Luster: Vitreous to waxy

Identified March 29, 2026More mineral →

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Physical properties

Formation & geological history

Formed from hydrothermal veins or within igneous cooling processes. Over millions of years, the parent rock eroded, and the quartz was transported by water. This specific specimen’s rounded shape is a result of fluvial (river) or glacial tumbling and mechanical weathering.

Uses & applications

Used as an abrasive, in glass manufacturing, and as a component in construction concrete. Polished pebbles are collected for landscaping, aquarium decor, and pocket stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Because of its hardness and chemical stability, it survives long journeys in riverbeds while other minerals break down into clay or silt.

Field identification & locations

Identify in the field by its ability to scratch glass and its lack of cleavage (it breaks in irregular, shell-like curves). Common in riverbeds, stream banks, and gravel pits globally. Collectors look for pieces with interesting inclusions or high transparency.