metamorphic
Quartzite
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: typically white to gray, but shades of brown, pink, or red occur due to impurities; Luster: vitreous to dull; Crystal Structure: Trigonal (granular texture); Cleavage: None/conchoidal fracture; Specific Gravity: 2.6-2.7.
- Hardness
- 7 on Mohs scale
- 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: typically white to gray, but shades of brown, pink, or red occur due to impurities; Luster: vitreous to dull; Crystal Structure: Trigonal (granular texture); Cleavage: None/conchoidal fracture; Specific Gravity: 2.6-2.7.
Formation & geological history
Forms from the metamorphism of quartz-rich sandstone under intense heat and pressure, typically in convergent plate boundaries. This specimen appears water-worn, likely collected from a riverbed or beach.
Uses & applications
Used as a decorative stone, in construction as crushed stone for roadbeds or railway ballast, and in the manufacturing of glass and ceramics due to its high silica content.
Geological facts
Quartzite is so durable that it often survives intense weathering that destroys other rocks; it can be resistant to chemical weathering and is harder than most other common rocks.
Field identification & locations
Identify in the field by its grainy, sugary texture and extreme hardness (it will easily scratch glass). Common in mountain ranges and fluvial deposits. Collectors look for pieces with unique banding or translucent properties.
More like this
