Mineral (occurring as a rolled clast)

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to light gray; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (though habit is rounded here); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to light gray
Luster: Vitreous to waxy

Identified April 20, 2026More mineral (occurring as a rolled clast) →

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Physical properties

Formation & geological history

Formed through hydrothermal processes or igneous crystallization from silica-rich magma over millions of years. This specific specimen has been chemically and mechanically weathered, likely in a riverbed or coastal environment, creating its rounded shape.

Uses & applications

Quartz is used in glassmaking, electronics (piezoelectric properties), abrasives, and as construction aggregate. Smooth pebbles like this are often used in landscaping and aquarium decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which has Slavic origins meaning 'hard'.

Field identification & locations

Identify in the field by its hardness (it can scratch glass) and lack of cleavage. Common in riverbeds, beaches, and gravel pits worldwide. Collectors should look for unique inclusions or clarity.

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