metamorphic
Quartzite and Quartz Pebbles
Tectosilicate - Silicon Dioxide (SiO2)
Hardness: 7 (Mohs scale); Color: Opaque white and translucent grey; Luster: Vitreous to waxy; Texture: Water-worn, smooth, rounded; Cleavage: None (conchoidal fracture).
- Hardness
- 7 (Mohs scale)
- Color
- Opaque white and translucent grey
- Luster
- Vitreous to waxy
Identified More metamorphic →
Explore Quartzite and Quartz Pebbles in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale); Color: Opaque white and translucent grey; Luster: Vitreous to waxy; Texture: Water-worn, smooth, rounded; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed through the metamorphism of quartz-rich sandstone under heat and pressure, then weathered and eroded by river or coastal wave action into smooth pebbles.
Uses & applications
Used primarily as decorative stones in landscaping, as a source for high-purity silica in industry, and occasionally in lapidary work for tumbling.
Geological facts
Quartzite is so tough that it often outlasts the surrounding rocks during erosion, leading to its prevalence as rounded pebbles in streambeds and on beaches.
Field identification & locations
Identify by its ability to scratch glass and its lack of visible grains compared to sandstone. Commonly found on beaches, riverbanks, and in glacial till throughout the world.
More like this
