metamorphic
Quartzite Pebble
Quartzite (primarily SiO2)
Hardness: 7 on Mohs scale; Color: Tan to light brown; Luster: Dull to vitreous (waxy); Crystal structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7.
- Hardness
- 7 on Mohs scale
- Color
- Tan to light brown
- Luster
- Dull to vitreous (waxy)
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: Tan to light brown; Luster: Dull to vitreous (waxy); Crystal structure: Hexagonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.7.
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone. High heat and pressure Recrystallize the grains. This specific specimen has been rounded and smoothed by mechanical weathering in a high-energy aquatic environment such as a riverbed or shoreline.
Uses & applications
Used in construction as aggregate, in glass manufacturing if pure, and commonly collected as river stones or 'worry stones' due to its smooth texture.
Geological facts
Quartzite is so hard that it can scratch steel and glass. Because it is chemically resistant to weathering, it often forms the tops of ridges and hills in ancient mountain ranges.
Field identification & locations
Identify by its extreme hardness and lack of reaction to acid. It is found globally in riverbeds, glacial tills, and coastal regions. Collectors value smooth, aesthetically pleasing shapes found in nature.
More like this
