mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Translucent to tan/creamy white (stained by iron oxides), Luster: Vitreous to waxy (when water-worn), Crystal Structure: Hexagonal (trigonal), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified March 18, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids or magma. This specific specimen is a 'clast' that has been weathered out of its parent rock (likely granite or metamorphic quartzite) and rounded by alluvial (water) action over many years.

Uses & applications

Common quartz is used in glassmaking, abrasives, and as a component in concrete/construction aggregate. Tumbled pebbles like this are often used in decorative landscaping or as garden mulch.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. These rounded pebbles are often called 'river rocks' and are durable enough to survive millions of years of travel through river systems.

Field identification & locations

Identify in the field by its hardness (it will scratch glass and steel), its translucent appearance when held to light, and the lack of cleavage planes. It is commonly found in riverbeds, glacial till, and gravel pits worldwide.