metamorphic

Quartzite

Metamorphic Quartz (SiO2)

AI-generated identification · may be incorrect

Hardness 7 on Mohs scale, vitreous to sugary luster, trigonal crystal structure in quartz grains, white to light grey color, non-foliated granoblastic texture.

Identified July 22, 2026More metamorphic →

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Physical properties

Hardness 7 on Mohs scale, vitreous to sugary luster, trigonal crystal structure in quartz grains, white to light grey color, non-foliated granoblastic texture.

Formation & geological history

Formed through regional or contact metamorphism of quartz-rich sandstone under intense heat and pressure, causing quartz grains to recrystallize into an interlocking matrix.

Uses & applications

Used as decorative stone, construction aggregate, railway ballast, and in the manufacturing of silica glass and ceramics.

Geological facts

Quartzite is extremely durable and resistant to chemical weathering. It often forms prominent ridges and mountain tops because it weathers much more slowly than surrounding rocks.

Field identification & locations

Identified by its sugary texture, extreme hardness (scratches glass easily), and fracture through quartz grains rather than around them. Commonly found in mountainous regions worldwide.