mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent yellowish; Luster: Vitreous to waxy (when river-worn); Crystal structure: Hexagonal (though not visible in this worn state); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent yellowish
Luster: Vitreous to waxy (when river-worn)

Identified June 25, 2026More mineral →

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Physical properties

Formation & geological history

Forms in a variety of environments, most commonly from the cooling of silica-rich magma or from hydrothermal veins. This specific specimen is a 'river pebble' rounded by water erosion through mechanical weathering over thousands of years.

Uses & applications

Used in construction, glassmaking, and as an abrasive. In this form, it is common as decorative stone in landscaping or as a 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 means 'hard'. Because of its resistance to weathering, it dominates sand and riverbeds globally.

Field identification & locations

Identify by its hardness (it will easily scratch glass) and lack of cleavage. It is found in riverbeds, beaches, and glacial deposits worldwide. Look for a smooth, rounded surface with no discernible layering.