mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Tan, beige, or milky white; Luster: Vitreous to waxy (weathered surface); Crystal structure: Trigonal (hexagonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Tan, beige, or milky white
Luster: Vitreous to waxy (weathered surface)

Identified April 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed through crystallization of silica-rich hydrothermal fluids or within igneous pegmatites. This specific specimen has been rounded and smoothed by water erosion through fluvial (river) or coastal processes.

Uses & applications

Common quartz is used in construction aggregate, glass making, and as an abrasive. Smooth river pebbles are popular for landscaping, aquarium decor, and pocket stones.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. This pebble shows discoloration likely due to iron oxide staining from long-term exposure to soil and groundwater.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (H=7) and its smooth, water-worn texture. It is a ubiquitous find in riverbeds and gravel pits globally.