Quartzite River Rock

Physical Properties

Hardness: 7 on Mohs scale; Color: Milky white with iron oxide staining (orange/brown); Luster: Vitreous to waxy; Structure: Granular/crystalline; Cleavage: None (conchoidal fracture).

Formation & Geological History

Formed when quartz-rich sandstone is subjected to heat, pressure, and chemical activity of metamorphism. This specific specimen has been rounded and smoothed by water transport in a river or glacial environment.

Uses & Applications

Used in construction as road aggregate, in glass manufacturing, and as decorative landscaping stones. Smooth specimens are often used in rock tumblers or as 'worry stones'.

Geological Facts

Quartzite is one of the most durable and weather-resistant rocks on Earth's surface. It is so hard that it can easily scratch glass and even steel.

Field Identification & Locations

Identify by its hardness (will scratch a steel knife) and its sugary/granular texture visible on broken surfaces. Commonly found in riverbeds, glacial deposits, and mountain ranges globally.

Identified on: 5/2/2026

Mode: Standard