metamorphic
Quartzite Pebble
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Light gray to white; Luster: Dull to vitreous; Structure: Granoblastic, non-foliated; Cleavage: None; Specific Gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- Light gray to white
- Luster
- Dull to vitreous
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: Light gray to white; Luster: Dull to vitreous; Structure: Granoblastic, non-foliated; Cleavage: None; Specific Gravity: 2.6-2.7
Formation & geological history
Formed from the metamorphism of quartz sandstone under intense heat and pressure, often within mountain-building (orogenic) belts. This specimen has been rounded and smoothed by water erosion in a river or beach environment.
Uses & applications
Used in construction as a decorative aggregate, in floor tiles, or as landscaping stones. Because of its hardness, it is also used in ball mills to grind other materials.
Geological facts
Quartzite is one of the most durable rocks on Earth's surface. Unlike sandstone, which breaks around sand grains, quartzite breaks through the sand grains because it is so thoroughly recrystallized.
Field identification & locations
Identify by its high hardness (it will scratch glass) and its lack of visible grains compared to sandstone. Commonly found on beaches, in riverbeds, and in glacial till.
More like this
