mineral

River Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 (Mohs scale); Color: Translucent grey to milky white; Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Translucent grey to milky white
Luster: Vitreous to waxy (when water-worn)

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed through crystallization from magma or precipitation from hydrothermal veins. This specific specimen has been weather-worn in a river or stream bed, a process that can take hundreds to thousands of years to achieve its smooth, rounded shape.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties), and as decorative river stones for landscaping and home decor. Polished versions are often used for 'worry stones' or crystal healing collections.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Specimens found in rivers are naturally tumbled by the movement of water and abrasive sediments, giving them a frosted or 'sea glass' appearance before being polished.

Field identification & locations

Identify in the field by its hardness (it can scratch glass and steel) and lack of cleavage. It is commonly found in riverbanks, beaches, and gravel pits globally. Collectors look for clarity and internal inclusions or 'rutilations' within the stone.