Quartzite Pebble

Physical Properties

Hardness: 7 on Mohs scale; Color: Tan to light brown; Luster: Dull to waxy; Crystal structure: Non-foliated granoblastic; Specific gravity: 2.6-2.7

Formation & Geological History

Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure, often found in ancient marine or fluvial deposits and smoothed by water erosion.

Uses & Applications

Used in construction as a sturdy aggregate, high-purity varieties are used in glass making and ceramics, or as decorative landscaping stones.

Geological Facts

Quartzite is so durable that it can survive long-term erosion and weathering that destroys other rocks, often resulting in smooth, rounded river cobbles and beach pebbles.

Field Identification & Locations

Identify by its ability to scratch glass and its lack of visible grains (unlike original sandstone). Frequently found in riverbeds, glacial tills, and along coastlines.

Identified on: 5/19/2026

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