mineral

Quartz Pebble

Silicon dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to waxy (when river-worn); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White to translucent
Luster: Vitreous to waxy (when river-worn)

Identified April 28, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to translucent; Luster: Vitreous to waxy (when river-worn); Crystal structure: Hexagonal/Trigonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65

Formation & geological history

Formed from cooling magma or precipitation in hydrothermal veins. This specific specimen has been rounded and smoothed by mechanical weathering in high-energy water environments like rivers or beaches.

Uses & applications

Common quartz is used for abrasive blasting, glass making, and as a component in concrete. Smooth pebbles are used for garden landscaping, aquarium decor, and home decorations.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It is extremely chemically stable and resistant to weathering, which is why it often remains as pebbles while other minerals break down.

Field identification & locations

Identify in the field by its hardness (it can scratch glass and steel knives) and lack of cleavage. Found globally in almost all riverbeds and coastal areas.