metamorphic
Quartzite
Quartzite (SiO2)
Hardness: 7 on the Mohs scale; Color: Yellowish-brown, tan, or gold due to iron oxide staining; Luster: Vitreous to sugary/glistening; Structure: Non-foliated, interlocking quartz grains showing tiny reflective mineral facets.
- Hardness
- 7 on the Mohs scale
- Color
- Yellowish-brown, tan, or gold due to iron oxide staining
- Luster
- Vitreous to sugary/glistening
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 the Mohs scale; Color: Yellowish-brown, tan, or gold due to iron oxide staining; Luster: Vitreous to sugary/glistening; Structure: Non-foliated, interlocking quartz grains showing tiny reflective mineral facets.
Formation & geological history
Formed from the regional or contact metamorphism of quartz-rich sandstone under intense heat and pressure, recrystallizing original sand grains into a dense quartz matrix.
Uses & applications
Widely used as crushed stone in construction, railway ballast, decorative landscaping gravel, and historically as a toolstone for flaking.
Geological facts
Because quartzite is composed almost entirely of quartz, it is extremely resistant to chemical weathering and erosion, often forming prominent ridges and hilltops in mountain ranges.
Field identification & locations
Identified by its extreme hardness (cannot be scratched by a steel blade) and sugary texture with visible tiny sparkling facets. Commonly found in riverbeds, glacial deposits, and mountain outcrops worldwide.
More like this
