Quartzite Pebble

Physical Properties

Hardness: 7 (Mohs scale), Color: tan, grey, or yellowish white, Luster: Vitreous to dull, Crystal Structure: Trigonal (microcrystalline), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.6-2.7

Formation & Geological History

Formed through the metamorphism (heat and pressure) of quartz-rich sandstone. Most quartzite pebbles are found in riverbeds or glacial deposits after being weathered away from larger parent rock formations.

Uses & Applications

Commonly used in construction as crushed stone, road ballast, or decorative landscaping gravel. In high purity, it is used for glass making and metallurgy.

Geological Facts

Quartzite is so hard that when it breaks, it fractures through the quartz grains rather than along the boundaries between them, unlike sandstone.

Field Identification & Locations

Identify in the field by its superior hardness (it will easily scratch glass or steel) and its granular, sugary texture. Often found in riverbeds or gravel pits as smooth, rounded stones.

Identified on: 4/29/2026

Mode: Standard