mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to milky translucent; Luster: Vitreous/Waxy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: White to milky translucent
Luster: Vitreous/Waxy

Identified April 13, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to milky translucent; Luster: Vitreous/Waxy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids or within igneous veins. This specific specimen has been rounded and smoothed by fluvial or marine attrition (water erosion over thousands of years).

Uses & applications

Used primarily for decorative landscaping, gravel, industrial glass production, and occasionally as a source of silicon for electronics.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. White 'milky' quartz gets its color from tiny microscopic inclusions of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and smooth, water-worn surface. Commonly found in riverbeds, beaches, and glacial till worldwide.