metamorphic
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Mohs hardness: 7, Color: white to light tan, Luster: vitreous to dull, Crystal structure: trigonal (microcrystalline), Cleavage: none (conchoidal fracture), Specific gravity: 2.63-2.65
Identified More metamorphic →
Explore Quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness: 7, Color: white to light tan, Luster: vitreous to dull, Crystal structure: trigonal (microcrystalline), Cleavage: none (conchoidal fracture), Specific gravity: 2.63-2.65
Formation & geological history
Formed from the metamorphism of quartz sandstone under intense heat and pressure, typically during mountain-building events (orogeny). The individual quartz grains recrystallize into a locked mosaic.
Uses & applications
Used extensively in road construction, as railway ballast, in the manufacture of glass and ceramics, and as a durable countertop material.
Geological facts
Quartzite is so hard and chemically resistant that it often forms the caprocks of mountain ranges. It is harder than steel and will easily scratch glass.
Field identification & locations
Identify in the field by its extreme hardness and grainy texture that looks like sandpaper but feels smooth and vitreous on fresh breaks. It is found in mountain belts and ancient shield regions globally.
More like this
