metamorphic

Quartzite Pebble

Quartzite (primarily SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale), Color: tan, cream, or light brown, Luster: dull to waxy (weathered), Structure: granular/crystalline, SG: 2.6-2.7

Identified July 15, 2026More metamorphic →

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Physical properties

Hardness: 7 (Mohs scale), Color: tan, cream, or light brown, Luster: dull to waxy (weathered), Structure: granular/crystalline, SG: 2.6-2.7

Formation & geological history

Formed through the regional metamorphism of quartz-rich sandstone under high heat and pressure, often hundreds of millions of years old. The rounded shape indicates water erosion in a river or beach environment.

Uses & applications

Used in construction as crushed stone or ballast, in specialized glass manufacturing, and as decorative river rock in landscaping.

Geological facts

Quartzite is so hard that it can scratch glass and steel; it is often more durable than the parent sandstone from which it originated.

Field identification & locations

Identify by its hardness and granular, sugary appearance on a fresh break. Commonly found in riverbeds, glacial deposits, and sedimentary basins worldwide.