metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
Hardness of 7 on the Mohs scale, color ranges from white and gray to pink or green depending on impurities, vitreous to dull luster, crystal structure is trigonal/hexagonal (microcrystalline matrix), no true cleavage (breaks conchoidally across grain boundaries), specific gravity around 2.65.
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 of 7 on the Mohs scale, color ranges from white and gray to pink or green depending on impurities, vitreous to dull luster, crystal structure is trigonal/hexagonal (microcrystalline matrix), no true cleavage (breaks conchoidally across grain boundaries), specific gravity around 2.65.
Formation & geological history
Formed from quartz-rich sandstone or chert under high temperature and pressure during regional or contact metamorphism. Geological ages vary widely from Precambrian to Cenozoic.
Uses & applications
Used in construction, railway ballast, manufacturing of silica brick, and occasionally as decorative stone or in landscaping.
Geological facts
Quartzite is extremely durable and resistant to chemical weathering, which is why ridges made of quartzite often form prominent mountain peaks.
Field identification & locations
Identified by its hard, sugary texture, inability to be scratched by a knife, and lack of bubbling when tested with hydrochloric acid (distinguishing it from marble). Found globally in mountainous regions and ancient cratons.
More like this
