metamorphic
Quartzite (River Pebble)
Metamorphosed Quartz Sandstone (SiO2)
Hardness: 7 (Mohs scale), Color: Brownish-tan due to iron staining, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (microcrystalline), Cleavage: Indistinct/Conchoidal
Identified More metamorphic →
Explore Quartzite (River Pebble) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: Brownish-tan due to iron staining, Luster: Vitreous to waxy, Crystal Structure: Hexagonal (microcrystalline), Cleavage: Indistinct/Conchoidal
Formation & geological history
Formed when quartz-rich sandstone is subjected to high heat and pressure, causing recrystallization. This specimen has been rounded by fluvial action (water erosion) over thousands of years.
Uses & applications
Used frequently as construction aggregate, high-silica raw material for glassmaking, and decorative landscaping stone.
Geological facts
Quartzite is so hard and chemically resistant that it often forms the caps of mountains and ridges, resisting erosion better than the surrounding rock.
Field identification & locations
Identify by its inability to be scratched by a steel knife and its grainy, sandpaper-like texture inside despite a smooth exterior. Found globally in river beds and glacial deposits.
More like this
