mineral

Quartz (Alluvial Pebbles)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless, white, pale yellow, or light brown; Luster: Vitreous to waxy (when weathered); Crystal Structure: Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Colorless, white, pale yellow, or light brown
Luster: Vitreous to waxy (when weathered)

Identified July 6, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or within igneous pegmatites. These specific specimens are alluvial, meaning they have been eroded from their primary source and rounded by water transport in rivers or streams.

Uses & applications

Used in glass manufacturing, electronics (due to piezoelectric properties), and as decorative gemstones or tumbling media in small scales.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded specimens, often called 'river stones' or 'alluvial pebbles,' are frequently collected as indicators for other heavy minerals like gold or cassiterite.

Field identification & locations

Look for a translucent appearance and a lack of cleavage. Hand-held identification includes checking for hardness (quartz can scratch glass) and examining for the presence of conchoidal (shell-like) fractures on broken surfaces.