metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
Hardness: 7 on the Mohs scale. Color: Typically white, gray, or pinkish with iron staining. Luster: Vitreous to greasy. Crystal structure: Trigonal (microcrystalline quartz grains fused together). Cleavage: None (fractures conchoidally). Specific Gravity: 2.65.
- Hardness
- 7 on the Mohs scale
- Color
- Typically white, gray, or pinkish with iron staining
- Luster
- Vitreous to greasy
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 the Mohs scale. Color: Typically white, gray, or pinkish with iron staining. Luster: Vitreous to greasy. Crystal structure: Trigonal (microcrystalline quartz grains fused together). Cleavage: None (fractures conchoidally). Specific Gravity: 2.65.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone or chert under high temperature and tectonic pressure. Geological age varies widely from Precambrian to Cenozoic.
Uses & applications
Used in construction, road aggregate, railway ballast, manufacturing of silica bricks, and occasionally as a decorative stone or in countertops.
Geological facts
Quartzite is extremely durable and resistant to chemical weathering, which is why ridges formed of quartzite often survive as prominent hills or mountain crests.
Field identification & locations
Identified by its high hardness (scratches glass easily), lack of effervescence with hydrochloric acid, and the fused sugary texture of interlocking quartz grains visible with a hand lens.
More like this
