metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

AI-generated identification · may be incorrect

Hardness of 7 on the Mohs scale, typically white, gray, yellowish, or reddish in color, vitreous to greasy luster, massive to granular crystal structure, conchoidal fracture, and specific gravity of 2.65.

Identified August 5, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed through the metamorphism of quartz-rich sandstone or chert under high temperatures and pressures, typically in mountain-building belts over millions of years.

Uses & applications

Used in construction, as crushed stone for roadbeds, decorative landscaping, in manufacturing glass, and sometimes as dimension stone.

Geological facts

Quartzite is extremely durable and resistant to chemical weathering, which is why ridges made of quartzite often form prominent mountain crests and hills.

Field identification & locations

Can be identified in the field by its high hardness (scratches glass easily), inability to be scratched by a knife, and the fact that it breaks across quartz grains rather than around them like sandstone.