Sandstone itself is not a metamorphic rock. It's a sedimentary rock, formed by the accumulation and cementation of sand grains.

However, sandstone can be transformed into a metamorphic rock through intense heat and pressure. The metamorphic equivalent of sandstone is quartzite.

Here's how it happens:

* Sandstone: Composed primarily of quartz grains, with some other minerals like feldspar and mica.

* Metamorphism: When subjected to high heat and pressure, the quartz grains in sandstone recrystallize and interlock, forming a very hard and durable rock.

* Quartzite: A metamorphic rock characterized by its hardness, lack of layering, and its ability to fracture in a conchoidal fashion (similar to glass).

So, while sandstone doesn't form quartzite, it is the precursor to quartzite through the process of metamorphism.