metamorphic
Quartzite Pebble
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Tan to reddish-brown with a white quartz vein; Luster: Dull/waxy on smooth surfaces; Structure: Granular/Crystalline; Very durable and resistant to scratching.
- Hardness
- 7 on Mohs scale
- Color
- Tan to reddish-brown with a white quartz vein
- Luster
- Dull/waxy on smooth surfaces
Identified More metamorphic →
Explore Quartzite Pebble 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: Tan to reddish-brown with a white quartz vein; Luster: Dull/waxy on smooth surfaces; Structure: Granular/Crystalline; Very durable and resistant to scratching.
Formation & geological history
Formed when quartz-rich sandstone is subjected to high heat and pressure, causing the quartz grains to recrystallize. This specific specimen has been rounded and smoothed by water transport in a river or stream.
Uses & applications
Commonly used as gravel, road ballast, or construction aggregate. Polished pebbles are used in landscaping and aquariums. Pure quartzite is used to produce glass and industrial silicon.
Geological facts
Quartzite is so tough that it often breaks through the quartz grains rather than along the boundaries between them. The white line visible on this specimen is a quartz vein filled by hydrothermal fluids during the rock's geological history.
Field identification & locations
Identified by its hardness (it will scratch glass) and lack of reaction to acid. Often found in riverbeds or coastal areas. Collectors look for unique inclusions or colorful veins like the one shown here.
More like this
