metamorphic
Weathered quartzite
Quartzite, composed predominantly of quartz (SiO₂)
AI-generated identification · may be incorrectPale gray, cream, and rusty tan with a dull to slightly glassy surface and irregular fractures. Quartz hardness is about 7 Mohs; quartzite is massive and nonfoliated, with no prominent cleavage. The image alone cannot confirm the identification; a hand lens or hardness test would help.
Identified More metamorphic →
Explore Weathered quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale gray, cream, and rusty tan with a dull to slightly glassy surface and irregular fractures. Quartz hardness is about 7 Mohs; quartzite is massive and nonfoliated, with no prominent cleavage. The image alone cannot confirm the identification; a hand lens or hardness test would help.
Formation & geological history
Forms when quartz-rich sandstone is recrystallized under heat and pressure, commonly during regional metamorphism. Its age depends on the source sandstone and metamorphic event, which cannot be determined from the photograph.
Uses & applications
Quartzite is used as building and paving stone, aggregate, and decorative stone; attractive pieces may be collected or used in lapidary work.
Geological facts
Interlocking quartz grains make quartzite resistant to scratching and weathering. Iron oxides likely contribute to the tan and rusty patches visible here.
Field identification & locations
Look for a hard, quartz-rich rock that commonly breaks across grains rather than around them; it occurs in metamorphic terrains worldwide. The rounded shape suggests natural abrasion, but the specimen’s location is unknown.
More like this
