metamorphic
Quartzite (River Stone)
Metamorphic Quartzite (SiO2)
Hardness: 7 on Mohs scale; Color: Tan to off-white with white vein inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7
- Hardness
- 7 on Mohs scale
- Color
- Tan to off-white with white vein inclusions
- Luster
- Vitreous to waxy
Identified More metamorphic →
Explore Quartzite (River Stone) 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 off-white with white vein inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.7
Formation & geological history
Formed from the metamorphism of quartz-rich sandstone under heat and pressure. This specimen shows significant rounding and smoothing consistent with transport in a river or stream environment.
Uses & applications
Commonly used as decorative landscaping stone, in construction aggregates, or as tumbled stones for hobbyists. High-purity quartzite can be used to produce silica sand.
Geological facts
Quartzite is so tough that it often outlasts the surrounding rocks during erosion, often forming the caps of ridges and mountains. It is more resistant to weathering than the sandstone from which it originated.
Field identification & locations
Identify by its hardness (it will easily scratch glass) and its lack of reaction to acid. Often found in riverbeds, glacial deposits, and mountain ranges. Collectors look for unique vein patterning or translucency.
More like this
