metamorphic
Quartzite
Quartzite (primarily SiO2)
Hardness: 7 on Mohs scale; Color: typically white, gray, or tan but can be reddish due to iron; Luster: vitreous to matte; Structure: granoblastic/non-foliated; Cleavage: none.
- Hardness
- 7 on Mohs scale
- Color
- typically white, gray, or tan but can be reddish due to iron
- Luster
- vitreous to matte
Identified More metamorphic →
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 but can be reddish due to iron; Luster: vitreous to matte; Structure: granoblastic/non-foliated; Cleavage: none.
Formation & geological history
Formed through the regional metamorphism of quartz-rich sandstone under intense heat and pressure. The individual quartz grains recrystallize and fuse together into a dense, hard mass.
Uses & applications
Used widely in road construction (crushed stone), as a decorative stone in architecture, for countertops, and as railway ballast due to its durability.
Geological facts
Quartzite is so hard and chemically resistant that it often stands out as high ridges or mountains because it erodes much more slowly than the surrounding rock layers.
Field identification & locations
Identify in the field by its extreme hardness (will scratch glass and steel) and sugary, crystalline texture. Found globally in ancient mountain belts and shield areas.
More like this
