Quartzite Pebble

Physical Properties

Hardness: 7 (Mohs scale); Color: Tan, brown, or yellowish due to iron oxide staining; Luster: Vitreous to waxy; Structure: Granular/Crystalline; Cleavage: None; Specific Gravity: 2.6-2.7

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone. High heat and pressure causes recrystallization of the quartz grains. This specific specimen has been further shaped by river or water erosion into a smooth pebble.

Uses & Applications

Used in landscaping, construction aggregates, glass making, and as a decorative river rock for gardens and aquariums.

Geological Facts

Quartzite is so tough that it can actually cut through steel and often breaks through the individual quartz grains rather than around them, which distinguishes it from sandstone.

Field Identification & Locations

Identify by its hardness (it will easily scratch glass) and lack of reaction to acid. Commonly found in riverbeds, glacial tills, and mountainous regions across the globe.

Identified on: 4/25/2026

Mode: Standard