mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with iron staining; Luster: Vitreous (glassy) to waxy; Crystal structure: Trigonal (hexagonal system); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent with iron staining
Luster: Vitreous (glassy) to waxy

Identified March 23, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids or within igneous pegmatites. This specific specimen is likely a water-worn river stone or glacial till, weathered and rounded over thousands to millions of years.

Uses & applications

Used in the manufacturing of glass, electronics (piezoelectric properties), abrasives, and as decorative landscaping stone. High-purity quartz is a precursor for silicon chips.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically very stable, which is why it remains as pebbles long after the host rock (like granite) has eroded into sand.

Field identification & locations

Identify in the field by its hardness (it will easily scratch glass) and lack of cleavage planes. It is commonly found in riverbeds, beaches, and gravel pits worldwide. For collectors, it is a basic but essential reference specimen.