metamorphic
Quartzite (Ferruginous Quartz)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Hardness: 7 on Mohs scale; Color: Pink to reddish-orange; Luster: Vitreous to waxy; Structure: Granular/Massive; Cleavage: None (conchoidal fracture); SG: ~2.65.
- Hardness
- 7 on Mohs scale
- Color
- Pink to reddish-orange
- Luster
- Vitreous to waxy
Identified More metamorphic →
Explore Quartzite (Ferruginous Quartz) 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: Pink to reddish-orange; Luster: Vitreous to waxy; Structure: Granular/Massive; Cleavage: None (conchoidal fracture); SG: ~2.65.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone. High heat and pressure cause quartz grains to recrystallize. The pink hue is usually due to iron oxide (hematite) staining during or after formation.
Uses & applications
Used as decorative stone in landscaping, as a building material (crushed stone), and occasionally in jewelry (as tumbled stones or cabochons).
Geological facts
Quartzite is so hard and chemically resistant that it often forms the capstone of mountains and ridges, resisting erosion better than the surrounding rock.
Field identification & locations
Identify by its ability to scratch glass and lack of reaction to acid. Often found in riverbeds or glacial tills where its durability allows it to survive long-distance transport.
