Quartz Pebble

Silicon Dioxide (SiO2)

Rock Type: mineral

Quartz Pebble

Physical Properties

Hardness: 7 (Mohs scale); Color: Creamy white to pale yellow; Luster: Vitreous/Waxy; Crystal Structure: Trigonal/Hexagonal (though rounded in this specimen); Specific Gravity: 2.65

Formation & Geological History

Formed from molten magma cooling or precipitation from hydrothermal veins. This specific specimen has been rounded and smoothed by water erosion through fluvial (river) or coastal transport over millennia.

Uses & Applications

Quartz is used in glass fabrication, electronics (piezoelectric properties), abrasives, and as decorative landscape gravel or tumbling media.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. This rounded form is often called a 'river stone'.

Field Identification & Locations

Identify by its hardness (it will scratch glass and steel) and lack of cleavage (it breaks with a conchoidal fracture if cracked). Found commonly in stream beds, beaches, and glacial deposits.

Identified on: 4/23/2026

Mode: Standard