metamorphic
Quartzite
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: typically white, gray, or tan with yellowish iron staining; Luster: vitreous (glassy) to dull; Crystal structure: trigonal (granular texture); Cleavage: none; Specific gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- typically white, gray, or tan with yellowish iron staining
- Luster
- vitreous (glassy) to dull
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: typically white, gray, or tan with yellowish iron staining; Luster: vitreous (glassy) to dull; Crystal structure: trigonal (granular texture); Cleavage: none; Specific gravity: 2.6-2.7
Formation & geological history
Formed through the regional metamorphism of quartz-rich sandstone. High heat and pressure cause the quartz grains to recrystallize and fuse into a dense, hard rock structure.
Uses & applications
Used as a decorative stone in landscaping, crushed stone for road construction and railway ballast, and occasionally for high-durability countertops.
Geological facts
Quartzite is so hard and chemically resistant that it often forms prominent ridges and hilltops because it resists erosion much better than the rocks surrounding it.
Field identification & locations
Identify by its ability to scratch glass and its granular, sugary texture that resembles sandpaper but feels smooth and solid. It breaks across grains rather than around them, unlike sandstone.
More like this
