metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
Hardness of 7 on the Mohs scale, color ranges from white and grey to pink, red, and purple due to iron oxides, vitreous to greasy luster, non-foliated crystal structure, conchoidal fracture with no true cleavage, 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 grey to pink, red, and purple due to iron oxides, vitreous to greasy luster, non-foliated crystal structure, conchoidal fracture with no true cleavage, specific gravity around 2.65.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under intense heat and tectonic pressure, typically during mountain-building events over millions of years.
Uses & applications
Used in construction, road aggregate, railway ballast, manufacturing of silica brick, and occasionally as decorative stone or in lapidary work.
Geological facts
Quartzite is extremely durable and resistant to chemical weathering, which is why quartz-rich sandstones transform into ridges and resistant mountain peaks.
Field identification & locations
Can be identified in the field by its hardness (scratches glass easily), inability to be scratched by a knife, and the way it breaks across the quartz grains rather than around them like sandstone.
More like this
