metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale. Color: White, light gray, yellowish-tan to light brown. Luster: Vitreous to sugary/earthy on rough surfaces. Texture: Granoblastic, fine to medium-grained with interlocking quartz crystals. Non-foliated or weakly foliated.
- Hardness
- 7 on Mohs scale
- Color
- White, light gray, yellowish-tan to light brown
- Luster
- Vitreous to sugary/earthy on rough surfaces
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, light gray, yellowish-tan to light brown. Luster: Vitreous to sugary/earthy on rough surfaces. Texture: Granoblastic, fine to medium-grained with interlocking quartz crystals. Non-foliated or weakly foliated.
Formation & geological history
Formed through the regional or contact metamorphism of quartz-rich sandstone. High temperature and pressure cause quartz grains to recrystallize, fusing them into a dense, extremely hard rock mass. Geological age varies from Precambrian to Cenozoic.
Uses & applications
Widely used as construction aggregate, crushed stone, decorative landscaping stone, building facades, flagstones, railway ballast, and historically for stone tools.
Geological facts
Quartzite is so tough that when it breaks, the fracture cuts directly through individual quartz grains rather than along the boundaries between them, unlike its precursor sandstone.
Field identification & locations
Identified in the field by its extreme hardness (scratches glass easily) and granular, sugary appearance. Found abundantly worldwide in mountainous regions, ancient cratons, and erosion-resistant ridges.
More like this
