mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: tan to milky white, Luster: vitreous to waxy (when water-worn), Crystal structure: Hexagonal (trigonal), Cleavage: none (conchoidal fracture), Specific Gravity: 2.65

Identified April 11, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: tan to milky white, Luster: vitreous to waxy (when water-worn), Crystal structure: Hexagonal (trigonal), Cleavage: none (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed through crystallization of silica-rich magma or precipitation from hydrothermal veins. This specific specimen is a 'river pebble,' meaning it has been rounded by mechanical erosion in water over thousands of years.

Uses & applications

Used in construction as aggregate, in glassmaking, as a source of silicon for electronics, and occasionally tumbled for inexpensive jewelry or decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek 'krustallos' meaning 'icy cold,' as ancient people believed it was permanently frozen ice.

Field identification & locations

Identify in the field by its inability to be scratched by a steel knife (7 on Mohs scale) and its lack of cleavage. Common in riverbeds, beaches, and glacial deposits worldwide.