metamorphic
Quartzite Pebble
Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Yellowish-tan to grey; Luster: Vitreous to dull (weathered); Crystal structure: Hexagonal/Trigonal (crystalline); Cleavage: None (conchoiodal fracture); Specific Gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- Yellowish-tan to grey
- Luster
- Vitreous to dull (weathered)
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: Yellowish-tan to grey; Luster: Vitreous to dull (weathered); Crystal structure: Hexagonal/Trigonal (crystalline); Cleavage: None (conchoiodal fracture); Specific Gravity: 2.6-2.7
Formation & geological history
Formed through the metamorphism of quartz sandstone under high heat and pressure, causing recrystallization into a dense, interlocking mosaic of quartz crystals. This water-worn pebble likely dates from hundreds of millions of years ago.
Uses & applications
Used in construction as road ballast or decorative stone; high-purity quartzite is a source of silica for glassmaking and metallurgical uses.
Geological facts
Quartzite is so durable that it can survive long-distance transport in rivers and high-energy coastal environments that would pulverize most other rock types. It is harder than steel.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel blade) and its granular, sugary texture on fresh breaks. This specific specimen shows river-worn 'chatter marks' or impact crescents on the surface.
More like this
