metamorphic
Quartzite river pebble
Recrystallized Quartz (SiO2)
Hardness: 7 (Mohs scale), Color: tan with brownish-grey banding, Luster: vitreous to dull, Crystal structure: granular/crystalline, Opaque to translucent
Identified More metamorphic →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 7 (Mohs scale), Color: tan with brownish-grey banding, Luster: vitreous to dull, Crystal structure: granular/crystalline, Opaque to translucent
Formation & geological history
Formed when quartz-rich sandstone is subjected to intense heat and pressure (metamorphism). The rounded shape is the result of mechanical weathering and erosion in a river or coastal environment.
Uses & applications
Large-scale quartzite is used for construction and road ballast. Smooth pebbles are often used for decorative landscaping, aquariums, and rock tumbling.
Geological facts
Quartzite is so hard that it will scratch glass and even surgical steel. It is more durable than the parent sandstone it originated from and is resistant to chemical weathering.
Field identification & locations
Identified by its high hardness, grainy 'sugary' texture on fresh breaks, and smooth, water-worn surface. Commonly found in riverbeds, glacial deposits, and beaches.
More like this
