mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs), Color: Tan to off-white, Luster: Waxy to dull (weathered state), Crystal Structure: Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified July 15, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs), Color: Tan to off-white, Luster: Waxy to dull (weathered state), Crystal Structure: Trigonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed from cooling silica-rich magma or precipitation in hydrothermal veins. This specific specimen was shaped and smoothed by water erosion in a fluvial (river) or coastal environment over thousands of years.

Uses & applications

Used in landscaping (river rock), construction aggregate, and as a raw material for glass making or electronics if high purity.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These smooth shapes are created by the constant tumbling against sand and other stones in moving water.

Field identification & locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Common in riverbeds and beaches worldwide. Collectors often value them as 'lucky stones' or for aquarium decor.