Quartzite Pebble

Physical Properties

Hardness: 7 on Mohs scale; Color: Tan, beige, or yellowish-brown; Luster: Vitreous to waxy; Crystal structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Formation & Geological History

Formed from quartz-rich sandstone subjected to intense heat and pressure (metamorphism). The pebble's rounded shape is the result of mechanical weathering and transport in water over thousands of years.

Uses & Applications

Commonly used in landscaping, road construction aggregate, and as high-silica raw material for glass manufacturing.

Geological Facts

Quartzite is so durable that it can outlast the surrounding softer rock for millions of years. It is often mistake for quartz or chalcedony, but its grainy texture confirms its sandstone origins.

Field Identification & Locations

Identify by its ability to scratch glass and its grainy, sugary texture when broken. It is extremely common in riverbeds and glacial deposits worldwide.

Identified on: 4/16/2026

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