Quartzite Pebble

Physical Properties

Hardness: 7 on Mohs scale; Color: yellowish-white to cream; Luster: vitreous to dull; Crystal structure: granular/interlocking; Cleavage: none; Specific gravity: approx. 2.65

Formation & Geological History

Formed via the metamorphism of quartz-rich sandstone under intense heat and pressure, causing quartz grains to recrystallize into a dense, interlocking mosaic of crystals.

Uses & Applications

Used as construction aggregate, railway ballast, decorative landscaping stone, and occasionally in glassmaking if rare purity is met.

Geological Facts

Quartzite is so tough that it often survives transport in rivers much longer than the stones it originated from; it will break through the quartz grains rather than around them like sandstone.

Field Identification & Locations

Identify by its extreme hardness (scratches glass) and sugary, granular texture; commonly found in riverbeds and glacial deposits as rounded cobbles.

Identified on: 5/1/2026

Mode: Standard