mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: tan to creamy white, Luster: Vitreous to waxy (when weathered), Crystal System: Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified May 30, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: tan to creamy white, Luster: Vitreous to waxy (when weathered), Crystal System: Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed from molten silica cooling in igneous veins or through hydrothermal activity. This specimen shows significant rounding, indicating it was transported and eroded by water in a river or beach environment.

Uses & applications

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

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Because of its high hardness and chemical stability, it survives weathering much longer than other minerals, which is why most beach sand and river pebbles are composed of quartz.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and translucent appearance when held to light. These pebbles are found worldwide in stream beds, glacial deposits, and coastal areas.