metamorphic
Quartzite
Quartzite (primarily SiO2)
Hardness: 7 on Mohs scale. Color: Tan, brown, or yellowish (due to iron oxides); Luster: Vitreous to dull; Crystal structure: Hexagonal (microcrystalline); Cleavage: None; Specific gravity: 2.6-2.7.
- Hardness
- 7 on Mohs scale
- Color
- Tan, brown, or yellowish (due to iron oxides)
- Luster
- Vitreous to dull
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: Tan, brown, or yellowish (due to iron oxides); Luster: Vitreous to dull; Crystal structure: Hexagonal (microcrystalline); Cleavage: None; Specific gravity: 2.6-2.7.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone. High heat and pressure cause the quartz grains to recrystallize and fuse together, creating a very dense and durable rock.
Uses & applications
Used in construction for road ballast, floor tiles, and countertop surfaces. Also used in glass making and as a decorative stone in landscaping.
Geological facts
Quartzite is so tough that it often survives intense weathering better than other rocks. In the field, it will reliably scratch glass and even a steel knife blade.
Field identification & locations
Identify by its grainy, sugary texture and extreme hardness. It breaks through the quartz grains rather than around them, unlike its parent sandstone. Commonly found in folded mountain belts.
More like this
