Here's why:

* Igneous rocks form from the cooling and solidification of molten rock (magma or lava).

* Sedimentary rocks form from the accumulation and cementation of sediments.

* Metamorphic rocks form when existing rocks (igneous, sedimentary, or even other metamorphic rocks) are transformed by heat, pressure, or chemical reactions.

Quartzite is formed when sandstone, a sedimentary rock composed primarily of quartz grains, is subjected to intense heat and pressure. This process recrystallizes the quartz grains, creating a hard, durable rock with a distinctive granular texture.