mineral

Quartz (River Pebble)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to yellowish-tan; Luster: Vitreous to waxy; Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to yellowish-tan
Luster: Vitreous to waxy

Identified March 28, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to yellowish-tan; Luster: Vitreous to waxy; Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from silica-rich hydrothermal solutions or cooling magma. This specific specimen has been chemically weathered and physically rounded by river transport over thousands of years.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, and as decorative landscaping gravel. High-quality crystals are used in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which means 'hard'.

Field identification & locations

Identify in the field by its hardness (it will scratch glass) and lack of cleavage (it breaks into irregular, shell-like curves). Commonly found in riverbeds and beaches globally.