metamorphic
Quartzite
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: White, gray, or clouded; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None, exhibits conchoidal fracture; Specific gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- White, gray, or clouded
- Luster
- Vitreous to waxy
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: White, gray, or clouded; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None, exhibits conchoidal fracture; Specific gravity: 2.6-2.7
Formation & geological history
Formed through the regional metamorphism of quartz-rich sandstone. Under intense heat and pressure, the individual quartz grains recrystallize and fuse together into a dense, crystalline mesh.
Uses & applications
Used extensively in road construction, railway ballast, as a decorative stone in architecture (countertops and flooring), and as a raw material for glass and ceramics.
Geological facts
Quartzite is so hard and chemically resistant that it often forms the caprock of mountain ridges. It is often confused with marble, but unlike marble, it will not fizz when exposed to acid and cannot be scratched by a steel nail.
Field identification & locations
Identify in the field by its extreme hardness and glassy appearance on fresh fractures. Look for it in mountainous regions or within metamorphic belts. It is one of the most durable rocks available for lapidary work.
More like this
