metamorphic

Quartzite

Metamorphic Quartzite (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 on Mohs scale; Color: Typically white to gray, can be pink or reddish due to iron oxide; Luster: Vitreous to greasy; Crystal structure: Trigonal (microcrystalline interlocking quartz grains); Cleavage: None (fractures conchoidally); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Luster: Vitreous to greasy

Identified August 1, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed through the metamorphism of quartz-rich sandstone under high heat and tectonic pressure, commonly over millions of years in mountain-building regions.

Uses & applications

Used in construction, as crushed stone for roadbeds, railway ballast, manufacturing of silica brick, and sometimes as a decorative countertop or ornamental stone.

Geological facts

Unlike sandstone, which crumbles easily, quartzite is exceptionally durable and weathers into resistant ridges. Famous for forming prominent mountain ridges worldwide.

Field identification & locations

Can be identified in the field by its sugary texture, vitreous sparkle from interlocking quartz crystals, and inability to be scratched by a steel knife.