metamorphic
Quartzite
Quartzite (primarily SiO2)
Hardness: 7 on Mohs scale. Color: White/Grey with tan staining. Luster: Vitreous to dull. Crystal structure: Hexagonal (microcrystalline). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.6-2.7.
- Hardness
- 7 on Mohs scale
- Color
- White/Grey with tan staining
- Luster
- Vitreous to dull
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/Grey with tan staining. Luster: Vitreous to dull. Crystal structure: Hexagonal (microcrystalline). Cleavage: None, exhibits conchoidal fracture. Specific gravity: 2.6-2.7.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone. High heat and pressure cause quartz grains to recrystallize and fuse together into a dense, hard rock.
Uses & applications
Used as crushed stone for road construction, railway ballast, and as a decorative stone in landscaping. High-purity quartzite is used to produce silica sand for glassmaking.
Geological facts
Quartzite is so hard and chemically resistant that it often forms the peaks of mountain ranges because it resists erosion much better than surrounding rocks like shale or limestone.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel nail) and grainy, sugary texture. It is commonly found in metamorphic mountain belts globally.
More like this
