metamorphic
Quartz-rich rock, likely quartzite
Quartzite; predominantly crystalline SiO₂, possibly with minor feldspar or mica
AI-generated identification · may be incorrectWhite to pale gray, granular and sugary with vitreous to pearly luster; quartz hardness is Mohs 7, with no cleavage and irregular fracture. The specimen appears compact but somewhat weathered, so exact identification is limited from the image.
Identified More metamorphic →
Explore Quartz-rich rock, likely quartzite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
White to pale gray, granular and sugary with vitreous to pearly luster; quartz hardness is Mohs 7, with no cleavage and irregular fracture. The specimen appears compact but somewhat weathered, so exact identification is limited from the image.
Formation & geological history
Formed when quartz-rich sandstone was deeply buried and recrystallized during metamorphism, typically during mountain-building; its age depends on the original sandstone and metamorphic event.
Uses & applications
Used as durable aggregate, road stone, building and decorative stone, and occasionally as a lapidary material. Attractive varieties may be polished for countertops or carvings.
Geological facts
Quartzite commonly breaks across grains rather than around them, making it harder and more resistant than its sandstone precursor. A scratch test with steel is useful, though quartzite should not scratch glass unless fresh quartz is exposed.
Field identification & locations
Common in metamorphic mountain belts worldwide, including the Appalachians, Rocky Mountains, Alps, and Scandinavian Shield. Confirm by checking that a fresh edge has interlocking quartz grains and does not crumble like sandstone; acid reaction should be absent.
More like this
