Quartzite is metamorphosed from

Quartzite is a hard, non-foliated metamorphic rock that originates from the metamorphism of sandstone [1]. This transformation occurs when quartz-rich sedimentary rocks, primarily sandstone, are subjected to intense heat and pressure, typically during tectonic movements or contact metamorphism [2]. During this process, the original quartz grains and silica cement recrystallize, welding together into a dense, compact crystalline structure. While sandstone is the primary protolith, other quartz-rich materials like siltstone or chert can also form quartzite [2]. In contrast, other options represent different metamorphic pathways: limestone metamorphoses into marble, shale into slate or schist, and granite into gneiss [1]. Quartzite is characterized by its extreme hardness and high silica content, often exceeding 90% [2].

Sources

1. [1] Certificate Physical and Human Geography , GC Leong (Oxford University press 3rd ed.) > Chapter 2: The Earth's Crust > METAMORPHIC ROCKS > p. 19
2. [2] https://www.sciencedirect.com/topics/earth-and-planetary-sciences/quartzite