Quartz (River Stone)

Physical Properties

Hardness: 7 on the Mohs scale; Color: Milky white to tan; Luster: Vitreous to waxy (when weathered); Crystal structure: Trigonal; Cleavage: None/Conchoidal fracture.

Formation & Geological History

Formed from cooling hydrothermal veins or igneous intrusions. These specific rounded stones were shaped and smoothed by the mechanical erosion of water in a river or stream bed over hundreds to thousands of years.

Uses & Applications

Used in landscaping, construction aggregate, glass making, and as a component in electronic quartz oscillators. Smooth specimens are popular for rock tumbling and decorative aquarium use.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'quarz', which has roots in Slavic meaning 'hard'.

Field Identification & Locations

Identify by its hardness (it will scratch glass) and lack of cleavage. Commonly found in riverbeds, beaches, and gravel pits worldwide.

Identified on: 4/13/2026

Mode: Standard