Here's why:
* Sandstone composition: Sandstone is primarily made up of quartz grains.
* Metamorphism: Metamorphism involves heat and pressure. These conditions cause the quartz grains in sandstone to recrystallize and interlock, creating a very hard and dense rock.
Other metamorphic rocks from sandstone:
While quartzite is the most common metamorphic rock derived from sandstone, other possibilities exist depending on the specific minerals present in the original sandstone and the intensity of metamorphism. These include:
* Metaquartzite: A slightly less metamorphosed version of quartzite.
* Gneiss: A banded metamorphic rock that can form from sandstone with impurities like feldspar.
* Schist: A metamorphic rock with a distinct foliation (layered appearance) that can form from sandstone rich in mica minerals.
