mineral

Quartz Pebble

Silicon dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Translucent to milky white with iron staining; Luster: Vitreous to waxy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Translucent to milky white with iron staining
Luster: Vitreous to waxy

Identified April 11, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of silica-enriched hydro-thermal solutions or magmatic cooling. This specific specimen reflects water-worn erosion, likely from a river or beach environment, often dating back millions of years depending on the local bedrock source.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), abrasives, and as decorative gravel. High-purity quartz is essential for semiconductor manufacturing.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is chemically and physically resistant to weathering, which is why it often remains as rounded pebbles after other minerals have dissolved away.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and the conchoidal (shell-like) fracture patterns on broken edges. Commonly found in riverbeds, gravel pits, and coastal areas.