mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Grayish-white, translucent; Luster: Vitreous to waxy (weathered); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Grayish-white, translucent
Luster: Vitreous to waxy (weathered)

Identified July 21, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Grayish-white, translucent; Luster: Vitreous to waxy (weathered); Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed from hydrothermal veins or the cooling of silica-rich magma. This specimen is a water-worn river pebble, having been smoothed by mechanical erosion over millennia.

Uses & applications

Used for lapidary tumbling, as aggregate in construction, or for the extraction of silicon for semiconductors and glass manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its resistance to chemical and physical weathering allows it to survive as pebbles long after other minerals have eroded away.

Field identification & locations

Can be identified in the field by its hardness (it will scratch glass) and its lack of cleavage. Found in riverbeds, beaches, and glacial till worldwide.