Quartz (River Pebble)

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky to translucent yellow/white; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal (though rounded by water); Cleavage: None; Specific Gravity: 2.65

Formation & Geological History

Formed from silica-rich hydrothermal fluids or igneous cooling. This specific specimen is a water-worn river pebble, likely transported and eroded over thousands of years in a high-energy aquatic environment.

Uses & Applications

Common quartz pebbles are used in landscaping, decorative ground cover, glass manufacturing (if pure silica), and as raw material for quartz watches and electronics.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which is of Slavic origin. It is piezoelectric, meaning it generates an electric charge in response to applied mechanical stress.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass and steel) and lack of cleavage (it breaks with a conchoidal/curved fracture). Common in riverbeds, beaches, and gravel pits worldwide.

Identified on: 4/22/2026

Mode: Standard