metamorphic
Quartzite Cobble with Quartz Vein
Metamorphic Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Brownish-gray with white quartz vein; Luster: Dull to vitreous; Structure: Granular/crystalline; Cleavage: None (conchoidal fracture)
- Hardness
- 7 on Mohs scale
- Color
- Brownish-gray with white quartz vein
- Luster
- Dull to vitreous
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: Brownish-gray with white quartz vein; Luster: Dull to vitreous; Structure: Granular/crystalline; Cleavage: None (conchoidal fracture)
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone under intense heat and pressure. The white vein suggests later hydrothermal quartz deposition into fractures. Common in riverbeds and glacial deposits.
Uses & applications
Used as construction aggregate, decorative landscaping stone, and occasionally for primitive tools or lapidary tumbling.
Geological facts
Quartzite is one of the most durable and weather-resistant rocks on Earth. This specific specimen has been rounded and smoothed by water erosion, likely in a river or coastal environment.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel blade) and its granular, sugary texture. Commonly found in areas with high tectonic history or glacial outwash.
More like this
