metamorphic
Likely quartzite pebble
Quartzite, composed predominantly of quartz (SiO₂)
AI-generated identification · may be incorrectPale gray, rounded and water-worn, with a dull to slightly glassy surface; quartz has Mohs hardness 7, a trigonal crystal system, no cleavage, and specific gravity near 2.65. The image alone cannot confirm the identification; pale chert or another hard, fine-grained rock is also possible.
Identified More metamorphic →
Explore Likely quartzite pebble in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray, rounded and water-worn, with a dull to slightly glassy surface; quartz has Mohs hardness 7, a trigonal crystal system, no cleavage, and specific gravity near 2.65. The image alone cannot confirm the identification; pale chert or another hard, fine-grained rock is also possible.
Formation & geological history
Quartz-rich sandstone transformed by heat and pressure into interlocking quartz grains, commonly during regional metamorphism; its age depends on the source rock and metamorphic event.
Uses & applications
Quartzite is used as crushed aggregate, paving and building stone, and occasionally for decorative or landscaping pieces.
Geological facts
Its interlocking quartz grains make true quartzite resistant to scratching and weathering; unlike marble, it does not readily fizz with dilute acid.
Field identification & locations
Look for a very hard, dense texture and grains that break across rather than around their boundaries. Quartzite occurs worldwide in metamorphic terrains; the pictured pebble is too small and feature-poor for a certain field identification.
More like this
