mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Translucent tan to greyish-white; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Translucent tan to greyish-white
Luster: Vitreous to waxy

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Translucent tan to greyish-white; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids or within igneous and metamorphic rocks. This specific specimen has been smoothed and rounded over time by water erosion in a fluvial (river) environment.

Uses & applications

Used in the production of glass, ceramics, and abrasives. In this tumbled form, it is often used for decorative landscaping, aquariums, or as a low-cost pocket stone for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which has roots meaning 'hard'. Many ancient cultures believed quartz was permanently frozen ice.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage. Look for the smooth, water-worn texture and translucency. It is found globally in riverbeds, beaches, and glaciers.