mineral

Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to yellowish-tan (due to iron staining); Luster: Vitreous to waxy (when water-worn); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to yellowish-tan (due to iron staining)
Luster: Vitreous to waxy (when water-worn)

Identified March 21, 2026More mineral →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or within igneous rocks like granite. This specific specimen has been eroded and weathered from its parent rock, then rounded and polished by the mechanical action of waves or rivers in a beach or fluvial environment.

Uses & applications

Common quartz pebbles are used in construction as aggregate, in landscaping, and processed for industrial silicon. Smooth beach pebbles are also popular in home decor, terrariums, and as 'pocket stones' for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These water-worn pebbles often survive much longer than softer minerals like feldspar or mica due to their high chemical and physical resistance.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and its lack of cleavage. Look for a translucent 'milky' appearance and a smooth, rounded shape on beaches or in stream beds. It is ubiquitous along coastlines worldwide.