mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to translucent tan, Luster: Vitreous to waxy (when weathered), Crystal structure: Trigonal/Hexagonal (usually eroded in river stones), Cleavage: None (conchoidal fracture), Specific gravity: 2.65

Identified March 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the crystallization of silica-rich magma or from hydrothermal veins. The rounded shape indicates secondary weathering through fluvial (river) erosion over thousands of years.

Uses & applications

Common quartz is used as an abrasive, in glassmaking, and as construction aggregate. Smooth pebbles like this are often used for landscaping, home decor, or as 'worry stones'.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. White pebbles are often called 'milk quartz' due to tiny fluid inclusions trapped during the crystal's growth.

Field identification & locations

Identify by its ability to scratch glass and its lack of cleavage. These are commonly found in riverbeds, beaches, and gravel pits worldwide. Collectors should look for unique banding or internal fractures that create mini-rainbows.