metamorphic
Quartzite
Quartzite (primarily SiO2)
Hardness: 7 on Mohs scale; Color: White to light grey; Luster: Vitreous to dull; Crystal structure: Non-foliated, granular; Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- White to light grey
- Luster
- Vitreous to dull
Identified More metamorphic →
Explore Quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 on Mohs scale; Color: White to light grey; Luster: Vitreous to dull; Crystal structure: Non-foliated, granular; Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under intense heat and pressure, causing quartz grains to recrystallize and fuse together.
Uses & applications
Used as crushed stone for road construction, railway ballast, and in the manufacturing of glass and ceramics. Also used as decorative stone in architecture.
Geological facts
Quartzite is so hard and chemically resistant that it often forms prominent ridges and hills because it resists erosion better than surrounding rocks.
Field identification & locations
Identify by its extreme hardness (it will scratch glass and steel) and its crystalline, sugary appearance. Found globally in fold mountain ranges.
More like this
